sound & music box ^el&ktor-elegiroM April 2QQ4 • WWW. :r n I I I ■ 1 : 770268 The leaders in PIC development iF USE All you need to get started with PiC industry standard/quaiity board Open the box and get coding Available with C compiler or use our PicScript to write programs using simple commands... NO ASSEMBLER, NO COMPILER, JUST WRITE AND RUN AUTOMATION SCRIPTABILITY PicDev Board with PicScript £99.00 (plus p+p) This is a complete development suite for the novice or non programmer. It is shipped with: ' ; : . PicDev Board • PicShell and PicScript software . Breakout board . Cables • Example scripts Both items req u ire q order: ■ PC with serial pod available Power supply adapter PicDev Board with C Compiler £1 65.00 (plus p+p) This is a complete development suite for the more advanced programmer. It is shipped with: . PicDev Board . PicShell and PicScript software • C compiler . Breakout board • Cables . Example scripts icoi sale pa gm , com k Tel : -44 (0 ) 1 7 9 2 89 1 92 7 ■ www. pagiTLeo.uk A TECHNICAL BACKGROUND AND (OVERLY) MODEST * How often do you hear technical types say, That's so good, it will simply sell itself ? In practice, we see that such judgements may not correspond to our everyday expe- rience. Many very good, technically sophisticated products have failed to win con- sumer acceptance, because it was not clear what benefits they provided For users. The field or electronics is not immune to this problem. We all take it for granted that electronics forms an indispensable part of our society, bur at the same time we find it unavoidable that there is less interest in the technical disciplines. Elekior Electronics has reflected these attitudes, but now it's time for a change. We com sider it our duty to make electronics and in forma Sion technology a source of inspiration for everyone who is even remotely interested in these subjects. To start with, we want to show that Elekior Electronics publishes articles that have been written with gusto - articles that are not ashamed to show that they are worth reading, even by the nan-initiated. And to inspire their readers. Our ultimate goal is to hear you say, "Mot only do I find it good, but so does he, and she. and everyone else. That's why we have modified the magazine cover, rearranged the standard teatures, added new ones and changed the layout of the articles. The new format features full colour, different photos and better-quality paper Et is intended to not only be informative and inspirational, but also to show thot elec- tronics can be fun. Regardless of whether this takes the form of the well-proven con- struction projects, reporting on new developments, reviving old expertise or reviewing interesting construction kits, sites and books. We hope that the enhanced E/ektor Electronics will be just as inspiring for you os it has been for us In the preparation phase during the past few months. In any case, please lei us know what you think. With an eye to the future of electronics and people who are interested in electronics, our aim is to prepare Elekfor Electronics to meet the challenge of the future, , , r International Editor [ad interim), Hon Mens ink elektor electronics Volume 30, Number 331, April 2004 ISSN 0268 45 i 9 Elekior Electronics asra at inspiring people to master electronics: at any per- sonal level by presenting construction projects and spotting devdopmertis in electronics and information tedino’Qgy. Elektgf Sedrancs is produced 2nd published by BeHor Efectronka (Pubfehing), P.C Bo- 9j. TLinccd£5 We .5 7t*J5 7WC Engsr-d “4 ---1 G 550 2C0657 - — 1 : 5 SO 2006 Ema3: - z~~; - :.e e: ~ “ t — - r~'~z n t -s =v= =b efnc^Ti r r- .-.scents bookshops zr-z : : r_ : 3 reta out- ata. ctr Qfi afijsengtcn: Beteor ElecERya-cs a pdbfehed I \ t-rraes a year vcah a double ssue for jdy & August, .’ ranr.-e £ etc' arc :r'.' Tt "nigpzhe 5 b'sz c ib ?"t" ~ -re - :^ Gecnrtan and Dutch. Together with frsrsciifead edaions the ntegazifie k cm csrodla- : " n me 3- than 5 1 coanir 3. International Editor .1:: • — an Editor: a - £■_ g ' ' International editorial staff: Many David Daymen, feff Ger^endori Ernst Krenr^sdtesijer. Guy Raedersdorf, 5^ van Recxj- laboratory staff: ■ ire 1 3ven bead :i: gr Ten G esbers g - P&J Glossers (design), Luc Lemmens (ddj^ Hatii Sdirafen Peter Verhoosd (PQ£ <8es£*n). Jan \%ser (prototypisig, Sofovarfe service) {■? ■ _ dept ' J se gen- "t r) Editorial secretariat Bedw^g Henoete^C&creteji iii@segrneni.tif) Page layout; £ : Cob Tin ,£_ - 23 Managing Director Publisher: r a_ Subscriptions .via Subsc? _bz- Service Lid.. Gses Reed Firm, Read, Tkzervirb TN5 THE, England 'Bcphcne: (+44) (0)1 580 200657, fez (+44) (0)1580 20061 6 Etna*: -v -.e 1 *v.5i ' z: _■ Rates aiyJ tejrra i v - =.eft the Sabscrcddr Order Fcmn Head Office: F-rg _ re _ : z., Tefephone: ( EQ. 80 * 75 M- 6 I 9 (MS Beak The Netheriarafs 2 46 43 BS 4 ^ -g \ 46 4570 i 6 Distribution: Seymour: 86 Newrnati Street Lcrrfan Wl P 3LD. Errand Copyright notice The dr£U3 besorlsed tm magazine- are for domesbe use onfiy. ^drawings, ptoto- grapris, prrited onztA board La>‘oOi5 and artdd teds pybfeheri sn Hie setriori of the magazine ore copyist b.v. ard may ret be r^prcdiKsd cr uirc.Ttided ri an ; t'z-rn =- b? z" . v-i -g I ZICXLCC ► "’g 5Ci r r."g an recard rg - .’.7 - - - an pin v*ithoui: prior written pemsssicn !ram the ftijfchert Suth wi^ten penrcs&on must dso be obtaried bdbre any part of this pufateon is stored ii a retrieval system c‘?-.r nature. ■■■:•£: :-r r 3-.. "i Ct-.vtZ - dE m^zane. Hie Bjfefebcr dies not accept responsi^y for Lalng stenSay swli patent: s 1 cr ere z^z:e^.c _ “ z Li y : ' :ll 7 i : 11 : :: :e i:-.: l'- _ " - >:■: zr : ::i g" i r : :: ue ire cotvc^ti " :: - t" Ferre — ~ rat irG ill; izi — 1 z _: ; i7r3 g.: ~ _ t“ f ret .*r an, i ::-i to 1 Tethntcal Quarias We C3fi only a^v^-eir tjoiesiioris or rcmidi ci geoe^ Sderest to o'jr readers, oonc&ri- ■g iteeoi r :: : :errr t»v : -t: - : t ~ r .: £*. t.-irc ■ , -iv : r 'u : *Tc-jnt ic” -r- - J - ret • t: :z i- . -■ 1 cc*-rtspdT. isr-ce, i"C --e are L^iabfe to respood to v/nhes and requests See moffiot-ora to, or addbonaJ . - i:: i::_: £ : n ; ' :i : ::il ^ -- - erices, pOesse use our OT (Efektor hem lracer) v.Fkti b on floppy tfc& {see Se-viea, 1. mL 11 .in:: 1 3 rcr trfi n cesorted " i - r map zre ’. .- ■ v ■ •. a imeted to PCBs, CD-ROf4s. d^c^tes. tTnaorociXitrafejs. GALs, RALs, 1 - and - - - 2 ' . : ' bsr d - z _ .ir = . _ : - : l n i : _ : : : : _ : ased : _ r ■ - l iii.i ii 'g ■; ird ^igure Ctrculation Cantrof: ’ r g e' •£' Sugmeci b.v, iOFK Printed n the Nethedards 4; JGtH-efrkicr electronics 3 10 Digitally Controlled High-End Preamp ( 1 ) Super sonic quality redefined. 32 DREAM TEAM How to build your own DRM software.... 28 Project c+ Data overtaking light/ if only this April. 18 VHF-Low Explorer Anyone out there on 70 MHz? Wavecatcher ... and improve reception quality. el®« iliiiranics S2 Pandora's Sound & Music Box Recycling old CD-ROM drives. 72 Drop-in Microcontroller Board Enter a jack-of-all-tradf" r popular micros. Contents VOLUME 30 APRIL 2004 8 no, 331 Construction Projects 10 Digitally-controlled High-End Preamp (1) 18 VHF-Low Explorer 52 Pandora's Sound & Music Box 60 kitchen table Low-power LED Flash 62 Drop-in Microcontroller Board Informative Articles 1 7 Elektor Electronics Year Volume CD-ROMs on Hard Disk 28 Project c+ 32 DREAM TEAM 38 start here leaking batteries - through-hole plat- ing - battery-backed RAM - SOT tem- perature switches - Poor man's DRM 44 Wavecatcher 58 of Mice and Light 68 review copy Audio Power Amps on the Internet - DSPs at I GHz Regulars 6 News & New Products 70 Mailbox 72 News & New Products 77 Readers Services 81 PCS layouts 82 Sneok Preview 82 Index of Advertisers mmELIKTOR-ELECTROttICS.CO.UK news & new pot icts SRD TRANSCEIVER CHIPS Long-range 430 - 950 MHz transceiver family with embedded MCU & ADC Nordic VLSI ASA have launched ihe nRF9E5 Transceiver with MCU, ADC and the nRF9G5 transceiver. The nRF9X5 compo- nents are designed for 430- 950 MHz wireless transceiver applications in industrial as well as domestic environment. Typi- cal applications include security systems, wireless data transfer, automatic meter reading, car alarm systems, poinR>F-sale sys- tems, sensors and various telemetry systems. Both ihe nRF9E5 and nRF905 □ re manufactured in an ultra modern 0.1 8-um CMOS process. The entire transceiver including all inductors and filters is integrated in □ single chip. The nRF9E5 transceiver has an embedded 8051 compatible MCU, and 4-tnput 1 0-bir ADC — Far the first lime providing the market with a complete low cost wireless system-orea-chip solution with a single 1 ,9 V-3.6 V supply. Voltage regulators are embed- ded on-chip to further lower the system cost, and to enhance per- formance. Both components include the unique 5hockBurst TV feature that ts used in both receive and trans- mit mode and greatly simplifies software and protocol design. ShockSurst” v includes features for CRC computation in both TX and RX mode, and address decoding in RX mode, greatly reducing the load and cast of the MCU running the RF proto- col, compared to existing trans- ceivers in the market. A crystal and a resistor ore the two com- ponents needed externally to make up a complete system □round the nRF9G5. The nRF9E5 requires an external EE PROM far external program storage. Both components are delivered in a Green" lead-free 32 pin 5x5mm QFN package. A unique feature of the nRF9X5 family is the ability to operate with the same layout and Identi- cal external components In the unlicensed European 868 A AHz ISM band as well as the North- American 915 MHz SRD band, easing logistics and lowering cost for manufacturers who have customers in both territories. getr.langeltrnd@nvlsi.no http;//www.nvlsLiw MENTOR & INTEL TEAM UP PCB Design Kit for Grantsdate chipset Mentor Graphics Corporation announced it has worked to pro- vide Intel Corporation with drop- in core layout (DCL) kits for use with the Mentor Graphics- Expedition 7 ’' PCB design flow for Intel's next-generation chipset, codenomed Grantsdale. The DCL kit, available through Intel, will provide an Intel re fer- ence motherboard design, inte- grating the CPU, chipset and other motherboard components for use with the Expedition FCB design flow, enabling personal computer motherboard OEMs and ODMs to shorten their design times. The DCL kit for Expedition will be available this year following the introduction of the new chipset by Intel. As microprocessor speeds con- tinue to Increase, it is becoming more complex to meet intercon- nect timing and signal integrity constraints while placing and routing the critical compo- nents, while also minimiz- ing the number of layers and overall size of the PCB, Intel Is addressing ibis challenge by provid- ing a reference mother- board design in Mentor's Expedition design solu- tion to its customers. The Expedition Series offers advanced fund ton- ality with ease-of-use for ihe creation of today's most complex PCB designs. The Expedition Series features the Indus- try's best place and route environment, powered by Auto Active® technology. The scalable product con- figuration of the Expedition Series allows designers to choose the right level of automation for their design needs. Expedition's tightly integrated systems design environment features a common database and common user Inter- faces and rules to ensure data Integrity Is maintained from con- cept to manufacturing. wvAv.merttor.rom/expedition/ deslgn_kits/ :~7cw : 6 dtklST sled rents - 4/2004 IEEE 1451.1 & SC2000 COMPLIANT Plug & play sensors Honeywell SensaSec has bunched its plug, play and calibrate sys- tems for its sensors and signal con- ditioning. The system is compliant \o IEEE 1451.4 standard far con- nectivity of sensors and associated signal conditioning. The transducer electronic data sheet (T.E.D.S) conjoining sensor specifications, calibration data and user defined location infor- mation is stored within the sensor. When connected to the 5C200Q or any IEEE 1451.4 compliant signal conditioning the sensor is interrogated for the TEDS informa- tion and automatically sets up and calibrates the signal condi- tioning with the sensor. IEEE 1451.4 compliant sensors and systems are set to revolution- ize the test and measurement market. Users will never have :o search for sensor calibration data sheets nor worry about the iden- tity of blind cable and connec- tors. The data will be right there, stored in the sensor and automat- ically recognized when the sig- nal conditioning is powered up. va 1 Av.hcHieyweS.com/s8tt sot EC -"y.i- UJWTS APPROACHING 3G network optimization Radioplon recently announced that their commenced!/ available WiNeS UMTS optimization solu- tion hos cut the cycle time for tuning the radio access network of a forge city by over 80%. WiNeS, a sophisticated, fully- featured 3G optimization toolset that has been developed to its current level of advanced func- tionality over several years, is available for use in-service today. This fact has generated immense interest in Radioplan s unique solution. Trials with major network opera- tors and equipment vendors have shown that Radioplan's proprietary software technology and flexible interfaces allowed for an exceptionally smooth inte- gration of the WiNeS toolset into the deployment process, and an extremely fast turnaround time far optimized radio network corn figuration results. Radioplan s WiNeS platform cuts redundant steps from the optimization process by bridging the gap between planning and measurement data, and by inte- grating the stages required info a single platform. This approach has the dual advantage of elimi- nating unproductive conversion stages while updating planning models with real world data. The subsequent efficiency of the sys- tem greatly accelerates the avail- ability of data for evaluation and optimization. A new document which outlines the thinking behind Radicplan's solution can be downloaded from their website. VAYWJKtopkm.com I MICROPROCESSOR-READY Cost optimized mass flow meters Sen si ri on presents a new gener- ation or moss Flow sensors with patented CMOSens E technol- ogy. Thd main advantage of the CMOSens® Ecoline is its very wide flow range (0-200 In/rntn with only one instrument] at an attractive price, especially for OEM applications. Thanks to the fusion of a thermal sensor element with the readout circuitry on o single semiconduc- tor chip (patented CMOSens 1 technology}, the EcoLtne achieves □n unusually high dynamic range of up to 1:1 '000, This indicates that a single CMOSens I E to Line meter covers the range af several traditional mass flow meters, which reduces the system cost significantly. The EcoLine presents an accu- racy of down to 3% of the meas- ured value over the entire range of 2.5 to 100% of the flow range. The digital output can deliver the measurement daia wish a speed af 5 ms. The rugged chemically inert hous- ing Is made af polycarbonate and Is resistant to pressure of up to 8 bar (1 1 6 psi). This opens up □ wide range of application vari- eties, for instance in process industry medico! applications or in the pharmaceutical industry as well os in chemical engineering. The CMOSens B EcoLine is par- ticularly suitable far OEM appli- cations requiring precision and speed at minimal cast. Modern technology permits a simple operation following the plug ond play principle. The dig- ital readout delivers the data via an RS-232/5P! interface. The supply voltage con vary between 7 and 18 VDC. vAwr.sensirioti.com 4 2004 - dsltlei tktf erics news & new products FOR EUROPEAN & US MARKETS Drop-In RF modules for SRD X EM ICS' 8 68 -MHz and 915- MHz Drop-In RF modules have been designed fa facilitate the development of wireless commu- nication applications and to reduce the time to market as they can be soldered directly onto a host board lo odd RF capabili- ties, Using these DP 1 203 mod- ules ranges of up to several kilo- metres may be achieved, through high output power and excellent sensitivity. The 868- MHz module is ETSI pr&cerliried and the 915-MHz module is FCC prenserlmed, All critical high frequency circuits are in a shielding can for extra protection against shock and EML No exiernol components [apart from, an antenna) are required. The module incorporates an on- board antenna matching circuit, making integration straightfor- ward even for engineers with no previous RF experience. The DP 1203 868-MHz ond 915- MHz modules can be soldered directly onto the main system board just like other compcx nenfs. The modules are suited far automated assembly systems for high volume production, which significantly reduces the cost of manufacture. The DP I 203 offers the unique advantage of high data rote communication up to 1 52,3 kbit/s. Offering high out- put power ond exceptional receiver sensitivity, the 86 8MHz radio module is suitable for applications conforming to the European [ETSI EN300-2201 and EN301 489-3) regulatory standards whilst the 915 MHz module conforms to FCC Part 15 applicable in the United States. The DPI 203 is the perfect mod- ule for complex wireless net- works; high speed data rate applications, voic e-over- RF, and applications where small size ond extremely short time to mar- ket are high priorities. With an 1 8 mm x 30 mm foot- print, the DPI 203 module fits perfectly into most customers' applications. Based on Surface Mount Technology (5MT) with components mounted only on one side, this module offers the advantage of being both very small and inexpensive. No addi- tional interface circuitry is required between the drop-in module and the microcontroller The modules are priced at below $10,00 in volume. Samples are ova liable ex-stock direct from XEM1C5 and will be deliverable in volume From mid-February 2004, vwAV.xemlcs.com FIGHTING POLLUTION No escape from the labyrinth Mast losers used in the manufac- ture or marking cf beards gener- ate hazardous dust and fume ihoi should be controlled by on extraction and Fillraiion system. This is also true in hand or machine soldering application producing solder fume. The cost of ownership of these filtration systems in terms of replacement filters can be a concern for the end user but the new patented Labyrinth Filter from Purex may just be the answer. Extensive trials with laser manu- facturers and long term, research and development work with filter media specialists have resulted in the new patented Labyrinth fil- ter that overcomes the disadvan- tages of current pleated paper and bag filter technology. The Labyrinth filter h a radical departure from current off the shelf filters and has been specif- ically designed for fillraiion of loser fume, A conventional paper filter can only capture par- ticles on a single thin face of media whereas the multi layered labyrinth filter media is deep and graded and so has a much greater dust holding capacity throughout without affecting air- flow. The greater dust holding capac- ity means that the end user does not have to change the filter as often and therefore laser down- time is kept to o minimum and because they buy fewer filters, the annual cos! of replacements is much lower, in same cases over 10 times less. Further savings are mode by the customer in shipping costs as compared to Sisjtdard Paper Filter Cross Sezisc-n ot Lotjrinth Filter Media L~ ted id ssm-a layer 0 0 s 0 0 0 0 O O 0 0 O O 0 0 O Q „o„o;o“,o . j : > : 0 O O 0 0 5 > O O O O ( 5 } -o„o“o„o, 3 j - 3 ; i 0 0 0 o°o 0 i 5 lin 5 i\ O „ O V 0.3,3,i 3 3 _o_oj53 5 5 „ O _ O , 5 ) l '3 1 ’ l. 0 rt 0 « 5 ^ ^ 5 *,£} ' 0 O !)j5 - 0 ^ > ,3 O O _ 5 _ 3 / '-2z:--=-z : - - Deeo fti_ r iaysr — capias rrcxe parties ir-fctjghout iFs tiJsptn bulky rigid filters which may be expensive to transport, the Labyrinth is small, compact and lightweight and is less likely to be damaged in transit. purex@purexltcLco.uk www.purexifitom I -1:1 5 8 dsklor deitroniB- 4/2004 POISED FOR WIRELESS APPLICATIONS Tiny synchronous dc-dc converters The ultra low ripple performance of Torex Semiconductor's new XC9215/I6/17 series of syn- chronous-reciitication type step- down DC-DC converters [n a chip scale USB-6B (2.0 x 1 .8 x 0.88 mm) package, mokes them an idea! choice for noise sensi- tive RF applications such as Blue- tooth ond nexTgene ration mobile phones. With □ built-in 0.5 P-channel driver transistor and G.6-_ N- channe! switching transistor, these highly integrated DC-DC converters require only the exter- nal connection of a chip induc- tor and two small ceramic capacitors to realise a stable power supply with an output cur- rent or 400 mA. Three different types of switching control are available. The XC9215 provides synchronous- reclifsed PWM switching control, the XC9216 automatically switches between PWM/PFM depending on output load, and the switching operation of the XC9217 can be manually con- trolled between PWM ond PFM/PWM using the device's CE/MODE pin. This MODE pin function gives the designer ulti- mate control over the switching mode of the 1C, which is a big advantage in RF applications. However, regardless of which ver- sion is selected, the 1C provides fast response, low ripple output and high efficiency over a broad range of output loads. Input voltage range is 2.0 V to 6.0 V, Output vo hog 2 is inter- nally programmable between 0.9 V and 4.0 V in Increments of 0.1 V. The switching fre- quency is 600 kHz or 1 .2 MHz, the higher frequency allowing the designer to use small chip style inductors. The new XC9215/ 16/17 con be supplied In either small SOT- 23-5 or ultra compact USP-6B (2.0 x 1.8 x 0.8mm) packages. www.tore3t.co.jp PREPARE FOR THE ELECTRICITY BILL New meter reading solution LogicaCMG, Dyomes and T- Mobile have bunched new' ways to allow companies to remotely get insight in their energy consumption. The energy metering and report- ing system of Dyomes, retrieves the data horn the remote energy meters. The metering doto is processed and maintained on logicaCMG's hosting environ- ment. This environment is con- nected to the energy meters through the T-Mobile wireless network. The solution enables companies to gain access to their daily energy consumption over the Internet. As a result of the liberalization of the energy markets many compa- nies need information about their energy consumption. Companies nave become aware of the fact that energy is just another Vow material' and that the costs should be managed. The solution does not only give Insight in the usage data, but also allows companies to reduce their energy costs. LogicoCMGs platform Mobi!e2U is connected to T- Mohile's bulk SMS server. In the future the platform will also be connected to the GPRS network. It can then also be used to remotely operate the energy installations, httpr//vAvw Jogkaang.com/ 4/2004 -ibklor tfedrGnks r 10 tSttJHti/F i«tWfVT«r) tu-*- ’J-S51U Figure 1 . Functional block diagram of the PGA23 1 i . The attenuation and gain are configured using a 3-wire serial bus. Analogue audio electronics appears to have entered a dormant stage. In our present age of CDs, DVDs and MP3, traditional preamplifiers have been relegated to the role of signal distribution and, primarily, adjusting the volume level. Our expectations for a modem high- quality preamplifier are that in addi- tion to being easy to use, it should perform these signal distribution arid volume adjustment functions with the greatest possible accuracy and the least possible distortion. And that is exactly where things start to get difficult. Volume controls are commonly imple- mented using potentiometers, which are available in a wide variety of price ranges and types. Since we are nor- mally dealing with a stereo signal, we need two mechanically coupled poten- tiometers. The decisive factor is the tracking of the two potentiometers, since this determines how closely the volumes of the right and left channels will match each other. Poor tracking is especially noticeable {and disturbing) at low volume settings. If we also want to have a balance control we need an additional set of coupled potentiometers, and the tracking errors will add together. The maximum permissible tracking error for audiophile’ sensibility is 3 dB, but ideally it should be less than 1 dB. As can easily be seen from Table 1, these values are clearly exceeded by normal carbon-film potentiometers, and even high-qual- ity carbon-film potentiometers have difficulty maintaining adequate track- ing accuracy with increasing age. An audiophile alternative to poten- tiometers is to use high-quality, multi- position rotary switches with close-tol- erance resistors. However, the right- hand column of the table shows that suitable special rotary switches having extremely low crosstalk and contact resistance cost around £80-90, which is rather expensive. The disadvantage of this solution involves more than just the price (we will need two or three such switches for the volume and balance controls and the input selector switch, if pres- ent), since rotary switches cannot be remotely controlled. If we wish to have the convenience of remote control as well as excellent tracking, there's no getting around a design using conductive-plastic poten- tiometers with a motor and the associ- ated control electronics and mechani- cal parts. This also involves consider- able effort and expense, and just about everything must be duplicated for a balance control The PGA23 1 I stereo audio volume control l€ Admittedly, the idea of using a ‘digital 1 IG for volume adjustment, and further- more controlling it using a microcon- troller, may evoke a sceptical frown from many an audiophile. Ten years or more ago, this scepticism would cer- tainly have been justified, but the semiconductor industry has made enormous progress in this area. All of the major functions can now be inte- grated into a single chip, with results that can easily hold their own against the best mechanical solutions. The Texas Instruments PGA2311 vol- ume control 1C used in this project is moderately priced and provides out- Table 1 . Tracking errors and price indications of various Types of volume control Type Tracking error [dB] Approximate price [£] Carbon-film potentiometer >3 3 High-quality carbon-film potentiometer 0.5-3 10-20 Conductive plastic potentiometer OJ -0,3 25 - 55 Rotary switch 0.1 80-90 Motor and accessories — 12 * 80 PGA2311PA 0.1 2.5-12 1/ ZGOi -elfj.br ekriruniu 11 Figure 2. Circuit diagram of the main circuit board, which is divided into an analogue part and a digitol part . standing tracking without any degra- dation of tracking accuracy when bal- ance adjustment is used, and it also has very good technical specifications. Another major advantage is that it can be digitally configured. This makes user-friendly operation possible ( including remote control). An example of a high-end builder who uses this technology is Jeff Rowland. The PGA2311, whose internal struc- ture Is shown in Figure 1, is a digitally controlled analogue stereo volume con- trol with certain refinements. The two channels can be independently adjusted over a range of -95.5 dB to - 31.5 dB in steps of 0.5 dB, which yields an adjustment range of 127 dB. The tracking error between the two chan- nels. as well as the absolute setting accuracy of each of the channels, is rG.05 dB. This naturally means that a balance adjustment can also be imple- mented without any problems, since the high absolute setting accuracy pre- vents any offset from occurring. Another noteworthy feature is that the 1C can directly drive 6GD-Q loads. The multiplexer (MUX) switches indi- vidual resistors to set the attenuation. After the attenuator, the signal passes through an output buffer, which can also provide gain via an adjustable feedback resistance. The IC is controlled via a serial SP1 interface. Clock signal SCLK transfers a single 16-bit word to the IC via the SD! line. The first eight bits set the vol- ume level for the right channel, while ihe second eight bits set the level for the left channel. The nihiLmum value (0) represents Mute, and the maxhnnni value (25b) represents a gain of -F31.5 dB. For fully noise-free switching, zero- crossing detection can be enabled via the ZCEN lead. If it is enabled, the IC analyses the music signal and atrempts to perform the switching dur- ing a zero crossing. If no zero crossing Is detected wi thin 16 ruilii sec ends, the switching is performed without wait- ing any longer. Due to system design constraints, the ramp function of the software does not work properly if zero crossing detection is enabled. In principle, four different types of ICs can be used in this circuit. Table 2 lists the differences among these ICs. The original design was developed for the Crystal (Cirrus Logic) type CS33IQ. The equivalent competitive product from Texas Instruments is the PGA231Q, which is not only pin -com- patible, but also has significantly bet- ter internal specifications, A particu- larly attractive feature of the latter iC is that it can handle signals up to 27 Vpp if the analogue supply voltage is Increased to 30 V. The improved type PGA231 1 has even better channel sep- aration. and the selected 'A version has a better specification for total har- monic distortion plus noise (THD-N). For this reason, we selected the PGA2311A for his project . We can also mention the PGA4311 in passing. This is a four- channel version of the PGA2311 and is only available in the SOIC package. It can be used with only minor modifications to the circuit board layout and software. The control centre The main circuit board, which forms the control centre for the preamplifier, requires surprisingly few components. This is due to ihe high integr al ion den- sity of the two ICs used here. By far the majority of the components are used to generate clean supply voltages. The circuit is split into an analogue portion and a digital portion. The digi- tal portion contains a Microchip FIC18LF452 microcontroller docked at 10 MHz by a crystal oscillator. This microcontroller has 8 -bit registers and 16-bit instruction words. Microchip has not shown much flair in assigning pari numbers to its PIC microcontrollers. For instance, the PIC16F84, PIC16FG28, FIC16F877 and PIG12F675 belong to the PIC 14 family, while the 12 ekltf&r detfrcjiio - 4/2D04 The project This project has a modular structure, so it can easily be adapted to individual preferences* It consists of a gener- al-purpose power supply board, an input selector board and the main circuit board, which holds the volume con- trol IC and microcontroller. An LC display module, a key- pad and an IR remote control unit complete the package. The hardware and software are described in this article, which is the first of two parts. The other two circuit boards are described in Part 2, which will appear in next issue of £/ekfor Electronics. Modifying the control pro- gram for the microcontroller is also described in Part 2. B/oct diagram of the preemptive r The option of connecting additional PGA23 J 1 ICs in parallel, os indicated by the dashed outline , is descnhed in Part 2. r ■ If you build all of the circuit boards as described, you will have a complete, remotely controllable pream- plifier with input selection and function display. However, you can also dispense with the input selector and use only the volume control capability. If you wish, you can also omit the display, or you can omit the volume control 1C on the main circuit board and use the remainder of the circuit as a remotely control lable relay circuit board for various applications* It is also possible to operate several volume controls in parallel, for instance in order to construct a multi-channel amplifier. For this purpose, only the volume control ICs have to be fitted to the main circuit boards for the additional channels. The control software for the microcontroller can be adapted to suit almost any imaginable application without reprogramming the microcontroller. P1G18LF452 used here belongs to the PIC 16 family. The PIC18LF452 has a Flash program memory with a capacity of 32 KB {which is adequate for the rather extensive software), 1-5 KB of RAM and a 256-byte EEPRQM. Its 31 stack levels provide adequate manoeuvring room for calling functions and proce- dures if the contents of all of the regis- ters are written to the stack to allow the called procedure to use the regis- ters. When control is returned to the calling procedure, the register contents are retrieved from the stack to allow the calling procedure to continue pro- cessing from the point where it trans- ferred control. If frequently used sub- routines are implemented using func- tions and procedures, the resulting interleaving of program execution can quickly exceed the capacity of a rela- tively shallow stack. Before discussing the software in any more detail, let's have a look at the peripheral resources available to the microcontroller. The volume control (ICS) is connected to the microcon- troller via the serial SP! bus. In addi- tion. the microcontroller can select the PGA23I1 using the C3 line, and it can mute the output by placing a Low level on the MUTE line. These four lines, as well as the data output line (5 DO), are externally accessible to allow several volume controls to be connected in parallel (as described in Part 2 of this article). Tire remainder of Port D and all of Port C are fitted with pull-down resis- tors (consisting of the two SIL arrays R3 and R4) and routed to pin header K5, to which the pushbutton switches for controlling the preamplifier are connected. K5 pins I&2 t .... 15&16 17&18 19&20 21&22 23&24 Function Channels 1-8 Volume Down Volume Up Volume Left Volume Right The functions are essentially self- explanatory but as you might imagine* additional functions are also imple- mented using combinations of buttons. All of the functions can also be selected using a remote control unit. IG3 is a 36- kHz infrared receiver, which filters, demodulates and cleans up the received light signal and boosts it to TTL levels, all without a single external component. An RC5 decoder is built into the soft- ware, so all types of RC5 remote control units (PMips, Grnndig, etc.) can be use d to control the preamplifier. The JR receiver is connected to RE2, which is one of the three Port E lines. Table 2, Volume control ICs suitable for use In this project. Type Dynamic range [dB] THD+N [%] Channel separation [dB] U out (max) [V pp ] CS3310-KP 116 0.001 -no 7.5 PGA23I OPA 120 0.0004 -126 27 FGA23I1P 120 0.0004 —1 30 7.5 PGA2311PA 120 0.0002 -130 7*5 dtar electronics 13 The configuration options are so mani- fold that without a clearly organised display presentation you could quickly loose track of where you are r panicu- I arly when programming the basic set- tings. Via Port A, the microcontroller software drives an LC display with two lines of 16 characters and back- ground illumination, in normal opera- tion the display shows the channel names and volume setting, while in Set-up mode it is used to select chan- nel designations and basic volume control settings. Pull-up resistor RIO connected to RA4 is necessary because this port lead has an open- drain output and thus cannot switch to a High level without a pull-up resistor. Trimpot PI adjusts the display con- trast, while trimpot P2 adjusts the brightness of the background illumina- tion. JF3 extends the adjustment range. The micro controller can switch the background illumination on or off via port line REG and transistor Tl. The microcontroller drives the relay board via K4, Each of port lines RB0-RB7 selects one of the eight audio inputs. The behaviour of the Status LED (Dl) can be configured using the Set-up menu. This is described in more detail later on, along with the signifi- cance of the three lines MCLR P RE 6 and RE7 that are led out from the board. The main circuit board has separate power distribution for the analogue and digital portions. The ground potentials must be connected at a suitable location via wire bridge JP2. The single - 5-V digital supply volt- age and the symmetrical ±5-V ana- logue supply voltages are stabilized in the traditional manner using fixed voltage regulators with the custom- ary buffer and decoupling capacitors. For all three voltages, 5.6-V Zener diodes are provided as 'backup' safety devices in case excessively high voltages appear on the outputs of the fixed voltage regulators. Operation After $ witch-on, the software checks whether reasonable value are located in the EEPROM. If tills is not the case, such as immediately after the micro- controller has been programmed, default values are loaded. Otherwise the software loads the stored values and configures the volume control accordingly. When a volume control button is pressed (Up, Down, Left, or Right), the software checks whether the adjust- ment is possible and whether the lower or upper limit of the adjustment range has been reached, Pressing the Up and Down buttons simultaneously causes the preamp output to be muted. Pressing the Left and Right buttons simultaneously restores the balance to the middle position, with the volume being set to the average of the values for the two stereo channels. If one of the input channel buttons is pressed, the channel is changed, with the output being muted during switch- ing. Alternatively the preamplifier can be configured via the Set-up menu to use a ramp. In this case, when the channel is switched the volume is first ramped down and then ramped back up again after the ch ann el change. An offset can be assigned to each channel, which is useful if the signal sources have different volume levels. The offset is applied to the set volume level when the associated channel is selected, and when a different channel is selected it is automatically removed. If an offset would cause one of the vol- ume limits to be violated, it Is ignored. The channel name selected using the Set-up menu is shown on the display. All of the functions of the preamplifier can be controlled using an RCB-com- patible remote control unit. Naturally, the preamplifier can be freely config- ured using the Set-up menu to allow an existing RGB remote control unit to be used to control all of its functions. The selected configuration settings are stored in the microcontroller EEPROM and are thus available each time the preamplifier is subsequently used. Set-up The software has default values for all configuration settings. All of the func- tions of the software can be adapied to individual needs via the Set-up menu, To enter the Set-up mode, hold the Channel 1 button pre s s e d whil e switching on the preamp. The Set-up configuration can only be modified using the control buttons on the preamplifier; it cannot he adjusted using the remote control. The buttons have the following functions in the Set- up mode: DOWN Next entry UP Previous entry LEFT Exit RIGHT Enter 1) RC5 IR Set-up Reads an RGB code from a remote con- trol unit, displays the code and assigns it to one of the following buttons: Channel 1-8, Down* Up* Left, Right* or Mute. Defaults Configured for a Grundig remote con- trol unit. Buttons LEFT Exit RIGHT Next 2) RC5 IR Test Reads and displays an RC5 code from a remote control unit. Intended to be used to check settings made using IR Set-up. Can also be used to test an RC 5 remote control unit. Button LEFT Exit 14 eleldw efemosks - 4/2004 3) Maximum Volume Sets the maximum allowable volume level in dB. Default 4-31.5 dB (maximum) Buttons DOWN Reduce volume level UP Increase volume level LEFT Exit 4) Ramp The ramp function gradually decreases the volume before switching channels and gradually restores it afterwards. The ramp function can be enabled or disabled, and the delay between suc- cessive volume steps can be config- ured. Enabling the zero crossing detec- tion function { JP1) can impair the oper- ation of the ramp function. Defaults Use ramp: Yes Ramp delay: 15 ms Buttons DOWN Use ramp: Yes/No Ramp delay: - 1 ms UP Use ramp: Yes/No Ramp delay: 4- 1 ms LEFT Exit RIGHT Next 5) Relay Test Energizes ah relays for testing, 6) Input Type This allows the input configuration to be set to either 8 channels (Single) or 2 x 4 channels (Double). Tnis is useful if you want to switch not only the signal leads but also the ground leads. The input type should also be set to Double for balanced signal sources. In the Double mode, the relays are switched hi pairs as follows: RE 1— RE 5, RE2+RE6, RE3-RE7, and RE4-rRE8. Default Single Buttons DOWN Single / Double UP Single / Double LEFT Exit 7) Offsets An offset can be denned for each chan- nel. It is applied when the channel is selected and removed when a different channel is selected. If applying an off- set would violate one of the volume limits (Mute or Maximum Volume), it is not used. The value is shown in dB. Defaults Channel 0-8: 0 dB Buttons DOWN - 0.5 dB UP + 0.5 dB LEFT Exit RIGHT Next 8) Channel Names Each channel can be assigned a name selected from the following list: Aux, Aux2 r CD t CD2, DAG. DAC2, DVD, DVD2, DVD-Audio, DVD-Audio2, Line, Line 2, Phono, Phono2, SACD. SACD2, Tape, Tape2, Tuner, Tuner2. TV, TV2, VCR, VCR2, Video, Video2, Sat, Sat 2, DCC. DCC2, MD. MD2, DAT, DAT2, PC, PC2. Defaults Channel 1: CD Channel 2: Phono Channel 3: DVD Channel 4: SACD Channel 5: DVD -Audio Channel 6. DAC Channel 7: Thpe Channel 8: Line Buttons DOWN Next list item UP Previous list item LEFT Exit RIGHT Next 9) Hardware Set-up Configures the type of hardware used. This only affects what is shown on the display. The options are Normal (pre- amp), Input Only (channel selection only), and Volume Only (volume adjust- ment only). Default Normal Buttons DQWN/UP Normal / Input Only / Volume Only LEFT Exit 10) LED Set-up Sets the LED behaviour Options: Delay Off, Always Off, Always On. Default Delay Off Buttons D OWN /UP D elay Off / Alw a y s G ff / Always On LEFT Exit 11) LED Set-up Sets the behaviour of the LCD back- ground ill umin ation. Options: Delay Off, Always Off. Always On. Default Delay Off Buttons DOWN/UP Delay Off / Always Off / Always On LEFT Exit 12) Power-up Volume Sets the switch-on behaviour. This menu can be used to configure two settings. The first setting controls the switch-on behaviour and has the fol- lowing options: Last (set the volume to 1 2004 - Elector dmrenks 15 Measured performance Confidence (in the data sheets) is good, but measure- ment (by the Elektor Electronics fab) is better! The results of the FFT analysis of a 1-kHz signal with an amplitude of 1 Veff indicate two things. First, the over- all harmonic distortion figure of 0.0012 % is dominat- ed by the induced 50-Hz mains noise (at -100 dB) if the measurement is made over a bandwidth of 20 Hz to 20 kHz, Second, the first three harmonics of the test frequency are located in the range of -1 1 6 dB to -1 1 8 dB, If the bandwidth range for the measurement is shifted to 100 Hz - 200 kHz, the THD+N value drops to only 0*0005 %. This Is a fantastically low value. In order to further reduce the effect of mains interfer- The harmonics of the 1 -kHz signal lie below - 1 16 dB . ence, it is recommended to separate the mains input and power supply board as far as possible* Fully enclosing the main circuit board and relay board (inside a tinned sheet-metal box located inside the main enclosure, for example] could also have a beneficial effect. Test results at unity gain (O dB) Nominal input sensitivity Nominal output voltage Maximum output voltage Input impedance Output impedance Bandwidth * Harmonic distortion (THD+N) * Signal fa noise ratio (5/N) “ Channel separation ' ’ Crosstalk ” * at Vout = 1 V ” with open input terminated in 560 Q 200 mV 200 mV 2.4 Vrms {THD+N = 0.01 %) 1 0 kQ [input selected) OQ (input not selected) < 0.6 n 0-3 MHz 0-150 kHz {gain 31.5 dB) 0.0005 % [1 kHz, B = 100 Hz - 22 kHz) 0.0012 % [1 kHz, B = 80 kHz) 0.002 % {20 Hz - 20 kHz, B = 80 kHz) 100 dB [B = 22 kHz) 1 13 dBA >88 dB (1 kHz) > 62 dB (20 kHz) < 98 dB (I kHz] < 88 dB {20 kHz) the same level as when the preamp was switched off), Mute, Mute — ► Last (muted on switch- on, with the previ- ous volume setting being restored after a button is pressed), and Preset (always use a configurable preset value). The second setting is the preset value. The current volume level can be stored as the preset value by pressing Up or Down* Default Last Preset values: Mute, Mute Buttons DOWN/UP Last / Mute / Mute — r Last / Preset (store current vol- ume as preset) LEFT Exit RIGHT Next 13) Restore Defaults Restores the pre denned default config- uration settings. This also occurs if a newly pro gramme d microcontroller without reasonable configuration val- ues in the EE PROM Is fitted. Default Volume: Mute Channel: 1 All others: see above __ _.4E 1 References [1] wwwdi.com h rip :/ / fee u s . iLc o m /d ocs/p rod /f o Id er s/pnnt/pga23 ] } .himl [2] v/. [ e ffrow iand.com/ Co ncen \ ro %20 Pc ge . h m www. \ e ffro wlo nd.com / d a cs * h im [3] Tap of the Range Volume Control', Elektor Electronics, OcL 2000, pp 32 ff. [4] www.ciiru5.com va*av. cirrus.cam/en/pubs/ rdDa [□sheer/ 33 1 O.pdF [5 ] vaw. m i crcch ip.com \a'av. m i c r cc h I p . c o m ,/d aw n log d/lit/ p I ine/p tc mic r o/fam i I ies / 1 8 Fxx 2/ 39564b.pdf 16 dd fer its - 4/2004 Elektor Electronics Year Volume CD-ROMs on Hard Disk Faster & comprehensive access Harry Baggen Annual Johrgang Amies Jaargang a sr«rt JtWl <*1 □>«€#- cr 1 .gM| The recently published Elektor Electronics 2003 CD-ROM has a useful extra for even easier use of several earlier volumes you may already have. It is now possible to copy most of our year volume CD-ROMs to hard disk using the program Diskmirror supplied. With a few tricks, you can even do so using relatively little hard disk space. Elektor Electronics year vol- ume CD-ROMs have been around for almost ten years and form a handy and com- pact way of archiving and searching thousands of Elektor Electronics articles. So fan these CDs had just one disadvantage: discs had to be physically exchanged if you wanted to look in a different year volume. Without special tools it was not possible to copy the contents of a year volume CD-ROM to hard disk and run it from there. This problem has been solved once and for all with the release of the volume-2003 CD. The pro- gram Diskmirror found on this CD now allows you to copy (nearly) ail CDs from the series to hard disk and access them there. One restriction exists regarding the CDs for year volumes 1995 and 1996. these having been produced, using a proprietary data for- mat which is incompatible with the current standard (Le., Adobe Acrobat Reader). Although the 1995 and 1995 CDs may also be copied to hard disk, the relevant archives need to be opened using their own browser pro- gram. Year volumes from 1997 through 2003 together occupy about 3 Gbytes of hard disk space. Although that is peanuts in view of today's hard disk capacities (which are often in excess of 100 Gbytes), we can well imagine that the sheer magni- tude of the collected archive is a bit too much for many older PCs sporting, say a 20- Gigabyte hard disk. Since all year volume CDs pro- duced by us contain all edito- rial articles in four languages (after all. we are an interna- tional publication), it Is possi- ble to select just one lan- guage when copying the 1998 through 2003 CDs to hard disk. First, create individual folders on the hard disk for every CD- ROM from 1998 onwards, using folder names like Elek_98. Elek_99, Elek 00, etc. These year-volume fold- ers may be contained in a larger folder named, for exam- ple, "EE_ Volumes 1 . Next, cre- ate a sub-folder named "Articles' in each of these year volume folders. Copy the pro- gram "easetup.exe 1 found on each year volume CD-ROM into the associated year vol- ume folder. Then copy the folder ‘E’ (English) from the year volume CD-ROM to the folder Articles' on the hard disk. On the CD, the folder b E‘ containing ail English-lan- guage articles may be found in the folder Articles'. Using the above method or selective copying the total size of the Elektor Electronics Archive 1997-2003 is limited to about 1.1 Gbytes. Having copied all hies and folders to their filial destina- tions on the hard disk. Diskmirror needs to be informed about the where- abouts of the various year vol- umes. This is done by enter- ing the relevant paths on the hard disk. Here at the editorial offices we use the HD version of our archive many times every day mainly to answer readers' enquiries and dig up our own articles. The access to the articles is extremely fast. 2 Q Vokines E G Ek*L00 - Z_j. Articles E - O Efekjn E G Ait#; *.- QE ■ E€3Ekk_Q2 S Q Aitides -Q E E Q Elek_C 3 E G AjfcSe* QE [ e £3 Efek _97 E Q EbkJS - _Li Ai teles &E - Q Ekk_9S B Q Aitiete* G E 4/20B-4 - Writer elec! ionics A low-cost NBFM receiver for 68-88 MHz This article, we hope, will have serious consequences. 4L * Jr A I \ ’V V l ■ Jf ' ^ t Jr fH&l Jot negative, mind you, because apart from enabling beginners to experience the thrill of picking up radio i « Mt, __ M . BB * * _« -* Jt f J H| traffic in a generally neglected band, the arrival of this inexpensive St-m receiver should help to get the IARU section of the 4-m band released to radio amateurs in countries all over the world in due course. eieitef etooftks- 4/MG4 Licence i Arr.ate-Lir Service : Secondary. Available on the basis nf 7 0MHz Nqiss: « oft- y : r erfcren op W o ik er sc n i c es ■ Inside or outs irfe thzUK}. (4 m) C E rtf ■*— r e Q V Power limit: 22c Permitted modes BW PER : Morse, telephony, RTTV, data, fax. Li ny ^ [ U 3STV IARU 1 < |3 < s | UK Usage 70,000 Beacons 70.030 Personal beacons 70.030 70.150 Meteor scatter calling SSB and 70133 Cross-hand activity centre CVV (inly 70.200 SSB CH calling 70,250 All modes 70.260 J MJF3 f calling / 703000 RTTY for catling Working -Q 3123 Digital modes 703230 Digital modes 703373 Digital modes ~ ■ 3 300 Emergency comms priority C hannelhed 70. 3623 Digital modes operation 7 03750 Emergency comms priority us\n% 1 2. 5kHz 70387$ Digital modes channel 70,4000 Emergency comms priority W 4125 Digital inodes 70.4250 FM simplex - used by GB2RS j— _ 70.4375 Digital modes 70.4500 FM calling 7 14623 Digital modes 7 70. 4S~5 Digital modes 1 Notes: 1 7 Q.Q35W Hz l 0. COS c s £ a ta : ed zr PS <3~ c >e in ihe J K. figure ? . If and when radio regulatory authorities eventually decide fo allocate the 4-m to radio amateurs then the IARU recommendations will he followed , with strong For many decades the UK has been home to the 4-m amateur radio band, also known as '70 MHz', and the IARU- approved band plan shown in Figure 1 is on the wall in many a radio shack up and down the country So far, only a few other countries including Ireland. Denmark and — quite recently — Croatia have followed suit by releasing the frequency range between 70.000 and 70.5000 MHz for use by licensed radio amateurs. Unfor- tunately, in many other countries the relevant frequency range is in use by government or military services which need to have a few arms twisted (pun intended) before they move out. Although it is too early to say whether or not the arrival of new communica- tion systems like Tetra f C2000 and Astrid on the European Continent and elsewhere will free up the 70 MHz band to amateurs, there can be no harm in increasing the pressure on various national radio regulatory authorities to do the necessary paper- work. At least in Holland and Poland, the word is out that amateurs are ‘interested 7 in the 70 MHz hand. Let's hope the pressure rises as the 4-m band is fantastic for VHF DX-ing, Elek- tor Electronics being an international publication, we will gladly assist in spreading the word in as many coun- tries as possible. What's m it tap m® While the radio amateur fraternity is poised to grab their share of the spectrum around 70 MHz, it should be noted that rhe 68-88 MHz band has other, equally interesting users and applications including Govern- ment, MoD and PMR {private mobile radio) communications (not encrypied in many cases }, security services, telemetry and the odd TV station. Unless you live in a really remote place, even a simple antenna guidance available from the UK example . in your loft will bring in a surprising number of stations using the 4-m band. Tune and Explore? Design considerations From the very start of this project, the design was to remain as simple as possible. This decision has important consequences as well as a back- ground we'd like to share with yon. Sure, a receiver for the 68-88 MHz band could be a double-conversion superheterodyne design employing a 10.7- MHz filter, a 10-turn pot for the tuning and a final intermediate fre- quency (IF) bandwidth of 15 kHz to suit NBFM (narrow-band frequency modulated) signals picked up at a sen- sitivity of 1 pV or so, not forgetting a squelch to make sure the receiver is quiet when nothing is received. Great shopping list, but such a receiver will be expensive as well as difficult to adjust by beginners. Next, please! The good news is that an attractive alternative is available in the form of the TDA7000 chip from Philips that’s been around for more than 10 years now, which is quite remarkable for a consumer-market chip. This ‘ ever- green' r then, contains a complete radio receiver with a very low IF of just 70 kHz. Okay t so image frequen- cies occur just 2 x 70 kHz = 140 kHz away from the desired signals, but that need not be a problem because on the positive side we do nor have to worry too much about the inpur filter- ing, Also, the IF filter responsible for 4/2C04 ■ c’ritor ekrirtmic 19 COMPONENTS LUST Resistors: R 1 = i 00 * Q R2= 1 50!cjQ R3=100» R4=22kH R5«3.30kQ FT =z?C logarithmic pete r>!'i a meter P 2 = 50 kQ iir : 5 cr potentiometer Capacitors: Cl =39oF C2-27pF C3 C6,C 1 4-1 QnF C4,C1 1 ,C 1 3 ,C 1 9,C23,C24,C25 r C26, S3 - M V 70 kHz OET r 7DA70OO XI rastifi'iz Figure 2. Block diagram of the single-conversion receiver. Note the low intermediate frequency of just 70 kHz which in our cose has a number of advantages! the selectivity may be realised as a simple R-C network, obviating the need for expensive and esoteric quartz or ceramic filters. Bl&ek dmgresm Even if you are noi a radio boffin, the block diagram of the proposed receiver in Figure 2 should be largely self- explanatory. The TDA7GQQ contains a muting circuit which is activated at a level of about 6 fJV. As we will want to use a whip antenna as the bare mini- mum, an RF preamplifier will have to be Inserted between the antenna and the input of the TDA7GOO. Everything from the output of the RF preamp right up to the input of the audio amplifier Is contained in the TDA7000. If you want to know everything about the chip, get a copy of the datasheet (see Web pointers). Inside § he receiver Figure 3 pictures the circuit diagram of our little receiver* MOSFET T1 at the antenna input provides a gain of ab out 18 dB across the band, driving the TDA7000 RF input via coupling capac- itor C5. The receiver's input imped- ance is 50 Q to match most types of coax cable available these days. A number of capacitors strewn around the TDA7GOO ensure an IF bandwidth of about 70 kHz. The VFO (variable fre- quency oscillator) inside the chip is tuned by a varicap { D 1 ) which gets its bias voltage from tuning pot P2. IC2, a 78L05, supplies the regulated 5 volts for the receiver chip, the preamp and, importantly, the tuning pot. The circuit configuration around the TDA7000 follows information from Philips on making the chip better compatible with NBFM signals. After all, the TDA7000 was originally designed for reception of VHF FM broadcast stations, which at 10CH- kHz deviation are much wider than the 'thin' FMR signals (3 kHz) were interested in None the less, as the IC will produce a rather low nett output signal, some extra amplifica- tion is furnished in the audio section by adding an electrolytic capacitor between pins 1 and 8 of the LM386 AF power amp (another evergreen). Hang on, where are the adjustments and the dreaded home-made coils in this receiver? Well there's only trimmer C20 to adjust the tuning to 68-88 MHz. C29= I OOnF G5,C12=1nF, lead pilch 5mm C7=l OOnF lead si ten 5mm C8=220pF C9.C 18=330 pF aoxopF Cl 5 C17-3nF3 lead Xch 5mm C1.6-I BQpF C2Q=22p^ PTi-t Trimmer C21=150pf The receiver employs off the shelf miniature chokes only, so there are 0 (say, zero) coils to wind. Build if! At this point, you should have enough confidence and inside knowledge' about the receiver to start building it. if necessary with the help of a friend with RF experience. If you do not have the means to make your own board, you can easily order a ready-made one through our Readers Services. The board, pictured in Figure 4 together with its external elements, is single- sided with a large copper plane at the solder side to assist in RF stability, screening and decoupling. There are many small ceramic capacitors on the board which need to be positively identified before they are soldered in place. The same goes for the three miniature chokes, the coloured bands on them indicating the value in micro- henries, The TDA7000 should be sol- dered directly on to the board. Toe 4-legged MOSFET T1 is mounted at the solder side of die board, perched directly onto four solder pads. The close-up photograph in Figure 5 should help to get our message across. We would suggest using a small diecast case from Hammond to house ihe receiver and the batter/. The case is then drilled to secure the volume pot, tuning pot and the loudspeaker. Bat- tery powering is not a must however, and you may decide to power the receiver from an existing DC source like a cheap mains adapter. Tnis will require one additional hole to be drilled and filed for the mains adaptor socket. ^sswemfs emd limif&ti@ns Due to the simplicity of the design, some inherent limitations should he 20 fleklor ekrtranks- 4/200 C 22 =] QQdF C27^2nF2 C28-lG|jF 16V radio! C30,C3 1 = IQOjiF 16V rodiol Inductors: L1 = ] GOnH (brown, black, sieved L2=33GnH (orange, orange, silver) L2= i 80nH [brown, grey, silver] taken into account. First, the receiver will be found rather susceptible to cross modulation, breakthrough and general interference from nearby FM broadcast transmitters. This not at ail surprising in view of the nearby fre- quencies (89-107 MHz) and power lev- els in the kilowatts range. Good shield- ing, coax cable and a tuned antenna for 4 m (see ‘Antenna’ inset) should remove most of the interference. Sec- ond, a small problem with spurious oscillation was discovered when the receiver's RF input is not terminated Semiconductors; D1=BB91 1 T1-BF981 ICUTDA7000 IC2=78L 05 IC3=LM386 N4 Miscellaneous; 8 ohm I wait miniature loudspeaker Dieeasf cose: e g., Hammond type 159GB 9V botfery [FP2 -6F22] wfrti ciip-c-n feeds PC8. order code 0204 f 6- i (see headers Services page or ww .v.eleic!or- efeclronks.co.ijk) ~2)TUNE 2$ VOLUME Figure 4. A drawing to show how the heard is connected to its external elements. The copper track layout may be bund elsewhere in this issue. IC 2 Figure 3. The circuit diagram of the VHF-Low Explorer has few surprises and proves the simplicity of the design. 4 20 G 4 - fhklor electronics 21 Gsrt Boars (42) hos been active in e'edronics from a young age. !n 1988 hs graduated in e'edrcr* ics at tm Palyreainic of Aikmaor in the Netherlands, Certs mc'n interest is RF efedranics, but also soft- ware and digital hardware. He has had aver *20 projects published in this magazine since 1 997 , including the successful Ai'rfcond Receiver,, the 20-m Band Receiver and the DD5 RF Signal Genera* tor. In the future, Geri hopes to write about Afme; micros in contra! of RF equipment, and possibly the design of a UHF sweep generator. He invites comments and suggestions by email □.baarsl j^aiello.H . with 50 Q. For the rest, nothing to stop Varicap selection or you from exploring the 4-metres band. fj,e deltO'C / delta ’V ISSUG {G£Dlifr-1} Web pointers TDA70QQ datasheet w^/w.semiconductors, philips. com/pip/ TDA7000.htm I #doto sheet 70 MHz info pace and news reflector: www.70m hz.org International Amateur Radio Union (IARU): wvAvJory.orc Radio Society of Great Britain (RSG8): www.rsgb.org t= i VtHz;Tj = 2S C 4-rr. hand m Ireland: wvav _qsl. ne \/ e i7 g 1/ vh f page . hlm#70m h z 70 MHz Vagi antennas (DK7ZB): www. q n ef/d k7zb /$ tart 1 _ hi m 7-olement Yagi far 70 MHz (MlCCZ): www, qsl.n et/ zr 6 dxb/ P R Oj ECTS/ A m B e a m / 4 MB e a m . htm Figure 5. This is as dose as we could get a lens fa the MOSFET at the solder side of the board . Use /he AiOSFET pinout drawing in the circuit diagram to get the device positioned the right woy around For some strange reason varicaps (or variable capacitance diodes) have always been rather elusive compo- nents, Try ibis: design, engineer and publish o design of instant T and you 'll find that the varicap you've specified after hours of careful researching has disappeared from the market at [ 7+ i day). Here at Elektor we're optimists by nature bur because we anticipate supply problems with the BB91 1 vari- cap specified for this present receiver, we thought we d give you a few clues to help you find equivalent types , The component values in the circuit diagram guarantee a tuning range of 68-88 MHz , with trimmer €20 defin- ing the edges of the tuning range and the capacitance ratio of the BB9J 1 defining the width of about 20 MHz. In other words , trimmer C20 shifts the tuning range and 01 determines the width of the tuning range. The two parameters have some interaction , of course . If you are only interested in , say, the 4 -m am a feur bond (70.0-70.5 M Hz) then a narrow tuning range is suffi- cient and you will have no trouble get- ting just about any old VHF varicap to work in the receiver, simply by adjust- ing C20 to a kno wri-good* signal in the band (ask for assistance from a local licensed radio amateur). if, on the other hand , you want every- thing from tow-bond TV (68 MHz) to police f MoD and government PMR (in some cases just below 87 MHz) then some thought should be given to the selection of the varicap. The Philips BB91 1 was chosen because of its relatively large capaci- tance range of 25 pF to 65 pF for a corresponding tuning voltage of 0.6 V to 5 V — see Figure A (courtesy Philips Semiconductors).. Thais right , fee capacitance presented by a vari- cap is inversely proportional to the voltage applied across the device! Mathematically, though , [delta- C / delta-V] is a dimensionless device con- stant which, in the cose of the BB9 1 /, worts out at about 9 for the linear parr of its capacitance range, if you can't get the BB9 1 1 locally there's no reason to abandon the proj- ect or send Blue Murder emails to fee Editor because there are lots of alter- natives, Do not be afraid to experi- ment In many cases , unlabelled vari- caps picked up at radio rallies or sal- vaged from on FM radio may be used, provided you know they are for VHF. Connecting a few varicaps in parallel ( stacking ") is perfectly legiti- mate in order to arrive of the desired AV/aC value and hence fee receiver's tuning span. elektor dettroflia - 1/2004 Features at a glance - Single conversion receiver - Frequency range 68-88 MHz (VHF*Low band) - Free^running VFO “ TDA7000 FM Radio Circuit modified for NBFM - MOSFET preamplifier - Single- board construction - On-board audio amplifier - 1,7 pV sensitivity for 12 dB SINAD [3 kHz deviation) “ Power supply 9-1 8 VDC, 20 mA {muted) Propagation = the total surprise factor The propagation of radio waves is a fascinating phenomenon because mast of if is guesswork and sheer surprise . That is not to soy the subject has not been studied extensively by researchers and radio amateurs — for from if , o number of underlying princi- ples have been described in scientific terms as early as the 1 920s by Nobel Laureate Sir Edward V Appleton { 1 892- 1 965). Appleton discovered that radio waves , depending in their frequency, were subject to refraction, reflection and (partial) absorption by certain regions of the earth's atmos- phere . These regions are marked by different electron densities and occur at heights of 60-400 km above the earth , The basic distribution is shown in Figure A . You will search in vain for the A, 8 and C regions. This is because Appleton first discovered the region around 1 00 km height and called tt " electron ' region . The D and F (actually FI & F2j regions were dis- covered later when the name E region was already established. Today, researchers employ extremely sophisti- cated radio equipment as well os observations from radio amateurs in an attempt to prove the existence of more layers in the atmosphere . Because if is easily Ionised , Jbe £ reg/on is favourable for reflection and refraction af signals in the 70 MHz and VHF bands in general . Apart from rather unexpected behaviour, usually during periods of high air pressure , the E region is also pre- dictable in that the electron density drops considerably at sunset due to o lesser degree of ionisation. As an aside, the E region reflects medium - wave band signals af night time when the absorption by the D region largely disappears. if will reach receiver R J as the far- thest location. However ; with a bit of help from Es the signal may be reflected and reach receiver R2 which, seen from T, is way below the horizon. In extreme case the signal may even bounce ' within the E layer and reach receiver R3. Es is due to the formation of 'clouds of densely ion i sod regions in the atmosphere at a height of 1 00-125 km. Es typically occurs during sum- mer months , but exceptions have been noted I Given a sufficient degree of ionisation ( sometimes helped by sunspot outburst), radio contacts via sporadic E have been made over dis- tances of 2000 miles and more. A good v/ay to check for Es activity is to use your receiver to monitor the signal strength of one of the many beacons in the 70 -MHz radio amateur bona, or TV stations near the low end of the bond. Many years ago t tbanlrs to a peat in sunspot activity coupled with massive Es cloud activity across ffre Atlantic Ocean , police cars from B % ...... .. Sporadic E (Es) is what we are after for our 70 -MHz receiver ; and the reason should be obvious if you look at Figure B „ Normally the range of a transmitter T using the VHF -Low band is governed by line of sight , so Boston and New York could be heard loud and clear in Europe, some sig- nals even making it across police repeaters on this side of the ocean. Stars if & Hutch Ten- four! 4/2GQ4 -ekkltf elcffron-Tcs 23 u No receiver is complete without a matching antenna. Commercial otter- ing 5 for the 4-m band being few and far between (or scrapped by PMR Peer owners ). we decided to present a design for a low-budget get-u- going dipole. Not sophisticated, want a directional antenna ? Then fry the links at the end of this article. Too difficult? It doesn "t get much simpler than this , so give this antenna design a try and you 'll be pleasantly surprised. The antenna is great for initial experiments even when installed on your attic . Our ingredients and tools are: - a length of 50 Q RG2 1 3 or RG8 coax cable (10.3 mm outside diame- ter) - a piece of copper pipe ■, 15 mm out- side diameter length 965 mm - two aluminium rods , 6 mm diameter length 1 m - two cable eyelets - o round T-junction box for electrical conduit 20 mm openings - some not too thin wire - a powerful soldering iron (> 50 v/otfs) - nylon or plastic bushes , 20 mm diameter - permission from the missus The drawing in Figure A is intended as o guide to constructing the anten- na . fiie copper pipe acts as a balun (balanced to unbalanced transformer),, not only matching the asymmetrical coax cable to the symmetrical dipole , but also stepping down the dipole impedance of about 72 Q to the cable impedance of 50 EL RF buffs will like to refer to it as a bazooka or sleeve balun. Unless you have electrical con- nection materials to fit to the red ends (like a 60- A electrical J ' chocolate block ' terminal strip), simply Batten and drill the ends of the aluminium rods to allow screws to be used for the connection with the cable eyelets . For extra rigidity,, the rads are fed through bushes (drilled to accept them) where they enter the junction box , and the box itself may be filled with potting compound or hard setting silicone sealant The other ends of the alu rods should be debarred, rounded off and sealed to prevent moisture ingress . if the antenna is to be used out of doors, the junction o f the copper pipe and the coax braid should be protect- ed as well This may be achieved by inserting the balun assembly in a length of 20 - mm dia conduit and fill- ing the lot with silicone sealant. All soldering to the coax cable should be On the rack! While tidying up the design of the VHF-Low Explorer for publication in this issue , an opportunity arose to have cur little receiver tested on a high-end instrument called the Rohde & Schwarz CMS 54 Radio Communications Service Monitor * This instrument (pictured here ) can perform automated meas- urements across the frequency range 0.4 MHz to 1 GHz which is not nor- mally within the capacity o f the RF test equipment available in the Elektor Electronics design laboratory. The of re r came from Mr. Ed Warmer PA 1 EW who is totally conversant with this piece at hit. handling and operat- ing if os if he were driving his car to the supermarket: Nat only the test done as quickly as possible to prevent deformation o f the PTFE (Teflon) core and consequently creating J impedance humps'. Variations on the theme are possible but be careful if you lack experience. Vbu may, for instance, decide to use much thinner material for the dipole arms (far instance, lengths of welding rad), thinking it will make no differ- ence as it is only the length that counts , Wrong f because your antenna will lose much of its broadband response and will present an accept- able V5WR at about 75 MHz ± 2 MHz only A larger rod diameter increases the bandwidth sa the anten- na can be used for the entire VHF-Low band (68-88 MHz). That is why base antennas use for PMR services in the VHP bands ore so thick / results obtained from the receiver are worth telling you about but also the basics of some of the specific tests the instrument can perform, as they may be unknown to many readers entering the radio hobby. A few fads had to be established first Our receiver is designed for narrow- band FM (NBFMi) reception between 68 MHz and 88 MHz f these values marking what is generally referred to os ine VHF-Low communications hand. As the receiver is of specific interest to radio amateurs f it was decided to tune it to 70- 2 50 MHz being the centre of the 4- metre band as defined by the IARU. The receiver being VFO tuned 24 elector e!ftfr&flk5-4/2G{H ™ RX"TEST HSfiDCapT' 1 ) 1.734 i. 70.25000 mz i.doqd tax XOflOkHz fiF HOB — i:lii 0,000 kHl uU FiF ' HOC \ (if l EO dB 0 HOD l I CODE iCOUHT U □1ST m 0,119 v 0.9821 Mi DFF 12.0 dB 1.000 kHz — dB \ T - W rhs skf: o.l m ihfe; 0,2 as/B * # PE £ BESK RBHSE • BMP |_! [ T — ! *00251 Jt. 1lJ[ PffH TIKE ? P 05 TXIE5T DV TrCT CNS ^ Local t!A H I to I mmw y s RF LEU 70.25000 mz }. 1.529 u g | ; : : : E0 d3 1.0005 Miz BF — kHz 3.00Q kHz HGD 0.000 Mz 1*1 HOD f HOD mm ms smacM fJ7s? SMCHBff ms 8Jds mnsfsis mm 1 mi M BiT M 3IPs 5 Ti'i/U OHD 0,2 us/fl ffl B and lacking a frequency readout, reverse thinking quickly lead to the CMS 54 being set to 70.250 MHz and cheerfully tuning the receiver until the test signal was audible. Hooray f it worts/ Receiver sensitivity measurement With the generator tuned to the receiver (or was it the other way around?) a great moment arrives — we re ready to decrease the RF out- put level on the generator until the receiver under investigation loses the signal The VHP -Low Explorer not having an adjustable squelch or squelch defeat switch, the transition from very noisy signal to 'muted' was found to be fairly abrupt (more about this further on). Receiver sensitivity is defined as the RF signal level at which the receiver's audio output signal achieves o certain signal -to- noise ratio . For NBFM receivers, SIN AD = 12 dB is consid- ered the standard — meaning that the signal we would like to hear is 12 dB above the sum of noise and distortion (hence the acronym SIN AD: an older measurement standard, S/N t employs noise only in the quotient). The RF sig- nal level is usually given in microvolts pd (potential difference) although emf (electromotive force) is preferred by purists . The CMS 54, then , had its RF signal output connected to the receiver input (by o length of RG58 coax cab/ej and the audio input r to the receivers audio output After a manu- al adjustment of the volume control on the receiver, on automated measure- ment is started on the CMS 54 which steps down its RF signal level until it measures an audio signal of 12 dB SINAD , The RF signal level at which that happens is frozen and displayed — see screertdump A. In our cose , a sensitivity of about 1.7 microvolts for 12 dB SINAD was obtained which is net bad at all given the sim- plicity of the design. The test was car- ried out using a test tone of 1 kHz and a deviation of 3 kHz. As you con see in the screendump, the CMS 54 also displays a real-time image of the receiver s output signal. Absolute sensitivity and squelch action Since the CMS 54 is capable of inter- preting audio signals with such amaz- ing precision it has no problems at all delecting when such a signal is passed or muted by the receiver The latter action is taken core of by the squelch ('mute') function built into the TDA7000 . An automated, stepped measurement was launched again , this time to establish the RF signal level at which the squelch closes. The result . aboirf 1.6 microvolts r can be seen in Screendump B. Ed kindly informed us that a squelch hysteresis of jus f 0.2 dB is not favourable for NBFM lis- tening, a value of 2-3 dB being the standard. A bit more hysteresis ensures that stations dropping into the noise do not cause the squelch to close abruptly. Rather, the receiver will ' fol- low r such Rutter-infested signals which, although barely intelligible in the noise will not cause the squelch fo 'chatter . The CMS 54 has o plethora of other functions for some really gruelling tests on radio communications equipment and in particular PMRs . We hope fo be able to use if again some time in the future . 4/2004 M Arc* efettrMiTLS 25 V Servicing Your Complete Prototype Needs 0 Prototypes at a fraction of the cast 0 Tooting and setup inriuded O Any contour O Fr4 1.6mm. 35pm Cu EURQCARD B1PTE 0 Industry standard quality 0 h iQ tV up senes runs O GAM CAD consulting + Tooting + Ptiotoptots + VAT £ 29 . 89 * . rf-irfiFO-tST CmWtFjsm jJ 1 I* . \ fisc+ffiBSiJiffUir "ts^ 60 oS 00‘ 3 ® 9 SirapJy jot tiki end order QHUME: WWW.PCS-POOL.COM | hMi?4 £ O K a d Gjf4?niQida. pmniTr r*ctr=.n!a * - , *. n andyscope HS 3 2 ch Resolution Menu - 12, 14 or 16bits Sample Rates - 5,10,25,50,100 Ms/s models / Oscilloscope / Spectrum Analyzer / Voltmeter plus! / Transient Recorder / Arbitrary Waveform Gen. / Two hi-z probes 1:1-1:10 / USB 1,1 or 2.0 / Windows OS- all i Tp Ltd 28 Stephenson Road, Industrial Estate, St Ives, Cambs, Pe27 3WJ Telephone: 01480 300695 Fa*: 014SQ 461654 info@itpl01.com www.ltp101.com www.tiepia.com Forest Electronics - PIC and AVR ANSI C Compiler Products FED’s ANSI C Compiler for PIC or AVR processors * Fully integrated editor with syntax highlighting, multiple pages etc. * Full project support - include and manage multiple source files, simulator, assembler files and notes- comments within one project • Fully Integrated simulator and waveform analyser step from C line to C Iine T or examine code in assembler form. 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Button Pressed, Byte Received etc,) • Automatically generates your base application including full initialisation, interrupt handling and main program loop • The complete C Compiler and AVR Simulator programs are Integrated Into AVIDICY - total editing / compilation / assembly / simulation support in one program • Also Includes the Element Editor to enable you to create your own components with ease, • Demonstration avail able from our web site Prices from £50.00 - full details from www.f ored.co.uk Forest Electronic Developments 12 Buldowne Walk, Sway LYMINGTON, Hampshire, 5041 6DU. 01590-68151 1 (Voice/Fax) Full details from -www.fored.co.uk Email - '‘info@fored.co.uk" VISA 26 Elektor Electronics 4 2004 Easy- PC for Windows from High performance Windows based PCB Design Capture > * ~ Simulation and Layout software at prices you'd expect from your local computer store! 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Manufacturers & designers of quality Transformers for over 20 years. • IVA-750VA size range, medium quantities • Mains, Audio, Loudspeaker & ferrite types • Specialise in Valve/Tube mains and output transformers. • Rewind/Replacement of rare/speciai transformers • A standard range of Valve/Tube Amp mains & Output Tx's (P/P, SE etc) is available through Mike Holme's web site: www.mc-h.demon.co.uk/transformers.htmi (Also, Valve circuits, Parts lists, Chassis & Advice) • Established supplier to Mapiin Electronics (www.maplin.co.uk) for over 15 years. Contact David Brooks l. Eng MNE (Proprietor) Phone : 01245 328174 Fax: (24Hr) 01245 328963 Email: DanburyElecTX@aoi.com 20 Cutlers Rd, Saltcoats ind. Estate, South Woodham Ferrers, Essex. CM3 5XJ (UK) ► **4 * * i mm 4 C compiler supplied * Compatible with most developmont tools * In-system programmable * Free Atmel debug simulator available * Peripheral drivers and libraries supplied 1 Increasing range of expansion modules 4 Full wob site support Check out Fiexlt at www.ennovi.co.uk ennoyiltd e *44 (0)t425 47SB84 se. I etje n novi .co ,u k Precisian measij re merit Embedded control intrinsic safety Internet n m be (Mud systems USB interface 4 2004 EEeklor Electronics 27 Data comms beyond light speed Research papers by their naiure are difficult for the average layman to understand. Here in the Elektor Electronics laboratory between the odd cup of coffee we spend much time studying scientific reports. A recent paper by a Japanese research group caught our eye because we were able to replicate the effects described using a very simple circuit and the results are so profound that it could change forever the way we send data. 28 e1=IcIm fbtlrtjm'c-4 7 '/.‘ Figure I , Experimental circuit for the Project c-r. The properties of light that most of yon will be familiar with are that it travels in a straight line at a speed, c, of approx- imately 3 x 10- m/s. We should not for- get to mention that this is only true when it is passing through a vacuum and not influenced by gravity. As soon as it enters another medium, light is slowed down and bent (refracted), In the latter part of 2003 M. D. LuMn and his colleagues at Harvard University announced in Nature [1] that they had successfully slowed down a pulse of light in a matrix of rubidium atoms such that it was stationary for a few hundred milliseconds before it was released and accelerated to regain light speed. The uses of this technol- ogy are manifold in the fields of quan- tum communications and photonics. Drawing on these techniques a team of Japanese researchers have adapted the technology (termed I- Ging) to accelerate precise (low frequency) pulses of electromagnetic energy along transmission lines to achieve incredi- ble propagation speeds. Inverting causality? The experimental set-up is shown in Figure 1. The pulse transmitter on the left of the diagram generates a signal pulse that is sent through the medium (either an optic fibre or simple cable) to the receiver circuit on the right hand side of the diagram. Two oscillo- scopes are used to display the signal pulse when it is introduced to the medium and recovered by the receiver. The purpose of Project Ct is to demonstrate that by careful matching of the pulse to the fundamental char- acteristics of the transmission medium it is possible to achieve vastly reduced propagation delays. The breakthrough It is often the case that a scientific breakthrough occurs by accident where unexpected or anomalous results suddenly cause the investiga- tion to veer off in a totally different direction. The story of this break- through is a case in point, it seems as though during routine network testing one of the research team mistakenly entered a frequency range of mHz (yes, that f s millihertz) rather than MHz (megahertz) into a programmable waveform generator. The resultant effect on the test circuit was truly bizarre and may have easily been dis- missed or overlooked had the researcher been less observant. Normally in the held of high speed communications we are accustomed to propagation delays in the order of picoseconds or even femtoseconds but provided we use the correctly profiled pulse shape (a fundamental I-Ging pulse containing no higher order har- monics) coupled to a transmission medium originally intended for much higher frequency signals it seems as though it is possible to accelerate the pulse to such an extent that it under- gees localised temporal inversion in its passage through the medium and arrives much earlier than predicted (hence c-r ). The experimental circuit The pulse generator in Figure 2 is quite straightforward and consists of a CMOS 555 timer IC together with two cascaded band-pass filters to produce the necessary pulse shape. The hirer resistors are all .1% tolerance metal him types with a value of 1 MQ (choose matched values where possible). Filter capacitors are low-loss foil types with 1% tolerance. The correct choice of components is critical to the success of the circuit, a fact to which any compe- tent audio engineer will attest. There are two possible power supply configurations for the circuit: either pins and minus 4,8 V consisting of eight NiMH AA type cells (if the TLG82 op-amp is used) or a single- ended 4.8 V supply if a precision rail to rail op-amp like the OP29G is used. In this case the negative pole of the supply must be connected to the earth and all minus supply connec- tions in the circuit diagram. To be sci- entifically rigorous the generator and receiver should be powered from sep- arate power supplies to avoid cross coupling but a common supply will suffice for this experiment. Once the circuit is completed the out- put waveform of the I-Ging generator can be observed on an oscilloscope. When SI is pressed a transmission pulse similar to that shown in Figure 3 will be generated and sent down the medium. Each square graticule repre- sents 1 second. 50-04 - dsklcr elsdionin 29 Figure 2. the i-Ging puke generator uses high precision components. os Figure 4. The regeneration amplifier The medium The choice of cable is vital in order to match the pulse profile to the charac- teristics of the transmission medium and thereby achieve the observed pulse acceleration. After much trial and error in the Elektor Electronics lab- oratory we coo eluded that a length of Uvisted-pair 100 Mbit/s Ethernet cable (CATS) operated in the sub-hertz fre- quency range gave the most consis- tent results. A cable length of 400 m was used in the prototype. In practice it is a good idea to cut it slightly longer so that it can be trimmed during testing to find its optimum length. The cable intro- duces a certain degree of attenuation to the low-frequency content of the pulse so the receiver circuit is pro- vided with some amplification to com- pensate. The receiver circuit diagram is shown in Figure 4 and uses a con- figuration similar to the transmitter. To operate reliably it is essential to ensure that the specified components are used throughout the circuit. The power supply can again either be sin- gle rail if you choose the OP290 op- amp or split -rail for the TL082, Ones the receiver has been carefully com- pleted and checked we can begin with the experiment B&ek t© re&iify Figure 5 shows the test configuration for sending and measuring the high- speed pulses. With an oscilloscope connected to the transmitter output and another connected to the receiver output it can be clearly confirmed that when push button SI is pressed, the transmitted pulse arrives at the receiver before it is detected as having left the transmitter] Even if you do not have an oscilloscope the effect is so pronounced that it can be demon- strated by substituting two simple LEDs at the measuring points and observing the events that occur when SI is pressed. It is clearly observable that the receiver LED is lit slightly before the transmitter LED and then extinguishes before the transmitter LED! Figure 6 shows the pulse wave- forms as seen on a scope. It may be necessary to adjust the length of the cable slightly if the effect is not observed. 30 elskiuf ekEtrcdss - 4/5CL4 The revolution begins The simple circuit described here replicates the findings of the original paper but only achieves a data rate of 0.5 b/s< To be truly useful this needs to be much faster, certainly in the region of Gb/s. To make the tech nology more practical a form of dynamically adaptive pulse shaping will also be necessary to compensate for the medium characteristics. Research into l-Ging is still in its infancy but these early results are so prom- ising that we will undoubtedly see its adoption in more and more applications as the technology matures. 030405 - 15 ' E Figure 3. The transmission puke. firVn _ £ m Q EB 5A*mV MTU ww 4H ft EH RMT □ ; i e s Figure 5. test configuration with two LEDs to demonstrate the effect , A two channel seeps can also be used in place of the LEDs. Figure 6. The impulse demonstrates localised temporal inversion . The principle of causality is a corner- stone of onr interpretation of the phys- ical world but the observed negative propagation delay of approximately 0,4 s through the transmission medium and receiver combination seems to conflict with our under- standing of this principle and will no doubt set alarm bells ringing for many Elektor Electronics readers, theoreti- cians and scientists. In practice this technology v/onld be used to send a stream of data at incredibly high speed rather than just a single pulse. The circuit was modi- fied to send a pseudo random data sequence and the results are shown in Figure 7. Tire received signal shows very low levels of distortion and noise and more importantly still exhibits identical negative propagation delay through the medium. The circuit described here is quite sim- ple and we feel that many sceptics amongst you will not be silenced until they have built the circuit for them- selves and witnessed what must surely be a new dawn for communica- tion science and computing. Can you explain the c-r phenome- non? If so, let us know as soon as you can so we can revert to the subject in next month's issue. I: Z~'.i . Refe rence [ 1 j http:/ /hkin.p hys ics.ho rvo rd. edu/ No ture426_ 638.pd f r t i -W > Figure 7. The technique applied to data transmission . 7 2Q04 - eEsklar 31 Burkhard Kainka j j I |,ppjj | § I Software DRM receiver Low-cost digital radio receivers for short- and medium- wave are not yet on the market. There is, however, software available for processing DRM signals on a PC which can eover in a , in features, and, ;pot least, in cost. V i ekkior eledrcnia-4/20(M gD m Multimedia Placet Ht □ ti * - / 1 . r-'.MC-i’cs /oumdine Newsservice Journaline - 1 < previous | up neat > : C- re Ere ish ne £ Still no signal from Beagle 2 The Etropean Space Agency has still not bean able to establish contact with a probe that a^Dgosed to have lancfed on titers on Thursday. Gn Friday, the sp^e agency failed on its third attempt to contact the Besgte 2 probe. Official at ESA space control centre in Darmstadt, Just south of Frankfurt, said ire US satellite. Mars Odyssey, was over the area on Mars where Beagle 2 was due to land for about 80 minutes, but no signals vva'e picked op. Beagle 2’s mission is to gather and analyse samples from ire surface of Mars, Figure l . DRM can also carry text and images, Hera is a example ham the Deutsche Welle (German world service } news service, displayed using the DRM Software Radio program via a multimedia player. WIieiliLT you use a modified world nidip or I he fijektur Hire- utmics DRM receiver to surf I tic digital wave, you will need a software decoder running on a PC. This program takes the signal input to (he sound card and decodes (he data stream from it, which it returns as audio data to the sound card for output. There are a) the moment two programs available: the DRM Software Radio' developed by Fraunhofer MS, and the open source project DREAM , run by Volker Fischer and Alexander Kurpiers of (he Communications Technology Insti- tute at the University of Darmstadt, A significant difference between the two programs lies in the requirements on the input signal. The standard intermediate frequency used is 12 kHz, putting the It) kHz-wide hand of the DRM signal between 7 kHz and 17 kHz. The DRM Soft- ware Radio allows a maximum deviation in the intermediate frequency of 5(K) I jv, whereas DREAM can decode DRM sig- nals anywhere in the range from 0 kHz to 24 kl lz. DRM with text and images *DRM Software Radio' is a commercial program and can he ordered online from wwvw.drmrx.org for about 60 Euros. Each user is given their own software key and is automati- cally registered. The user can then take part in the DRM field trials and send in reception reports. Reception repons, especially from Europe, can certainly influ- ence broadcasters' plans. The DRM Software Radio homepage gives information as to which stations can be received in which areas. The function ofthe software as a DRM demodulator and decoder has already been described in the arti- cle * Bui Id your ow n DRM Receiver" project in the previous (March 2004 j issue of Elrktor Ehcmmies. DRM can carry more than just speech and music. As well as the ‘audio service’, information such as the name of the station and news head lines is also broadcast: these can be viewed as a scrolling or as a steady display. Some broadcasters also transmit images or other information using a formal similar to the World Wide Web. 1 he DRM Software Radio program makes die so addi- tional services available via a multimedia player. When a par- ticular service is available, a click in the corresponding area in the w indow starts the player. After a delay while the requested data is collected, it is displayed. In ibis way. for example, the Deutsche Welle (German world service) trans- mitter in Jiilich on 6140 kHz has recently started an additional service called 'Journal ine\ carried alongside the audio signal. A click in the audio window opens the multimedia player; in the background news summary information (in both English and German) is collected, and. after a delay, the pages of news can be viewed. This service works even when reception conditions mean that the audio signal breaks up: the new s text still gels through, although it may take a little longer Figure 1 shows an example from the English-language Jour- naline ? service. Open Source Project In contrast to lahe 'ready to run’ DRM Software Radio, the DREAM open source project requires a little preparatory work. The authors have made the program available only as C++ source code ( hit p://sou rceforuc. net/p r* > i eel s fdnn/ i . Dis- tributing the compiled version DREAM.EXE is not possible for copy right reasons, as patent-protected components are used. We shall look at these components individually, and present a step-by-step guide to compiling the project yourself, written by Thors ten Godau DL9SEC. The complete project, along with advice on compilation and on the additional libraries required, can be found at w ww.tUT damis tad t .de/fb/et/uci/fcuei/mi tarbeiter/vf/DR M/DR M .hi m I and at hit p://w vv w. tu -damn st ad t .de/fb/et /tie t/d n n Ji t n 1 1 . The aim ofthe project was to develop an installable DRM software (receiver with basic functionality. The project, in C++. was begun in June 200! and version 1.0, which supports 4/MM'd&hui deftE&rsiu Wo y back in 1987 researchers at the Fraunhofer Institute started ro develop an audio encoding method that made use of psycho-ocoustrc effects. The result was called ISO-MPEG Audio Layer 3 a.k.a. MP3 — and it became the standard for the 1990s. MPEG Layer 3 achieves CD quality in stereo al a data rate of II 2-1 1 8 kbit/s. the new DRM standard using ihe F A AD 2 library, has been available since 1 7 December 2003. Although the software can be freely distributed under the CM' General Public Licence t GPL), that is not to say that there arc no third-party rights attached to it. In certain coun- tries use of the software by be in breach of patent law. The project is intended for those who w ant to find out how the DRM data stream is decoded, to learn about the softw are algorithms used, and then help to improve the softw are. If you only w ant to evaluate the quality of DRM transmissions, the authors recommend installing the commercial DRM Software Radio. distributed w ithout restriction. It is also not certain w h ether free use of FAAD2 will still be permitted as DRM is devel- oped further. We should nevertheless warmly welcome this opportunity for those interested in DRM to gain access to this new technology. Here are Thorsten Godau A comments on how to proceed. The first requirement fur compiling the DREAM source code for Windows is a working installation of: Microsoft Visual C— \ 6.0 Sen ice Pack 4 or Service Pack 3 is required for compilation, along w ith Trolkech QT 2.x, The following libraries are needed: IFTW. Qwt and FAAD2. We shall now look at these components in more detail: Qwt sQt Widgets for Technical Applications) is a library of GUI components, including graph plotting and controls. The entire Cs-+ source code is independent of the underlying oper- ating s\ stem and is used so that DREAM can run under Win- dows as well as under Linux. The library can be downloaded from hup://tjw LSQiircei~Qrge.net/ . FF'TW (the Fastest Fourier Transform in ihe West) was devel- oped at MIT by Maiteo Frigo and Steven G. Johnson, The package can be dow nloaded from http://ww w. fttw .org . DREAM uses the fast Fourier transform to analyse the indi- vidual carriers in the DRM signal in terms of amplitude and phase. The data obtained from these carriers is assembled to form the complete data stream, w hich includes both audio and multimedia components, FAAD2. by the Dutch company AudioCoding.com. includes the DRM-specific algorithms for decoding the received digital data, A AC ( Advanced Audio Coding) is t he TSO high quality audio coding algorithm developed by leading companies AT&T Dolby Laboratories. Fraunhofer ITS and Sony, w hich is also used in the Fraunhofer 1 IS DRM Softw are Radio. MPEG-2 and MPEG-4 AAC are also implemented. Version 2 also implements decoding of HE (High Efficiency) AAC streams. FAAD2 may be installed for private and scientific use under the GNU General Public Licence, although of course any patent restrictions must be observed. This is one of the reasons that a compiled version DREAM.FXF cannot be - Microsoft Visual (Studio) O- V6.0. and either - Visual C-r-r Sendee Pack 4 and Processor Pack for 5P4, or - Visual CVr Service Pack 5 and Processor Pack for SP5 Then proceed as follows: - Download the non commercial version of QT (QTAYIn V2.3 NC) from Trolkech at http: w w w . trol i te ch ,c orti download/qt download nDncomm JitFQl and install it 'use the standard paths). - Download the source code of DREAM V 1.0 (or higher) from h tip: // prdo w n I o a d s . s o u rce f o rge , ne t/d mi drm I (LzipMownload (select one of the mirrors ). -Download the precompiled FFTW package from h t tp:/Av \v w.iu -damistad t .de/fb/e t/u et/fg u et/tn i tar he iter/ yffPRAEdow nloadAYi nl- 1- 1 Min sr z 1 p . - Download the precompiled Qwt package from h t tpi//w w w.tu -darmstadt . dd fb/el/u et/ fgu et/mitarbe i ter/ vf/ORM/downloadAVinOW Tlnsi.zip . - Download the FAAD2 package from http:// w w w tu-darm st ad t.de/ fb/et/uel/f gu ct/mi tarbe i t er/ vf/DRM/dow n load. 'W 'in FA A D2SRRNew InsLzio. : — Create directories and copy in the precompiled files: - Create a directory called, for example, C:\vcprojeets - Open drm_l_Q.zip and unpack it into subdirectories of C:\vcprojects, - OpeeWmFFTWInst.zip. Copy the files libfftw.lib, fftw.h and rffiwJi from ihe subdirectory VI ib into the director. 34 deader slsdrorits - 4/ZQQ4 In 1997 the cooperation between the Fraunhofer Institute and large companies like AT&T, Sony and Dofby culminat- ed in the MPEG*2 Advanced Audio Coding (AAC) method. AAC achieves high quality' thanks to 1 -48 audio channels and sampling rates between 8 kHz and 96 kHz. Using Spectral Band Replication Technology (SBR) developed by Coding Technologies the data reduction efficiency con be doubled without loss of quality. mp3PRO is the MP3-compatibh implementation of SBR. ft is for available as a plug-in for the current version of the famous Nero Burning ROM software. The combination of AAC with band widllv extend eel SBR was originally marketed as a a c PLUS by Ceding Technologies. Having been standardised by MPEG as a one of the MPEG-4 audio profiles, the system became known as MPEG-4 High Efficiency (HE’AAC). This recently introduced standard allows full CD quality in stereo ot 48 kbit/ s, very good stereo quality at 32 kbit/s and 'parametric' stereo in FM radio quality at just 20 kbit/s* The latter is employed for DRM since December 2003. MPEG-4 HE AAC is also available as a plug in far Nero Burning ROM. C : \vc proj e e i$\ J mf J i bs . Open \YinQWTIn 5 l.zip. Copy all ihe files i .lib imd Jit from the subdirectory lib into the directory C :\vc p roj ec is\ d rm\l i bs . Open \\lnFAAD2SBRNewlnst.zip and unpack it into sub- directories of C Avcprojecls. - If DREAM.EXE is to be run on a computer where QT is not already installed, first copy the file qt-rm230nc.dll from the directory C:\qt\bin into C:\Proeram FiieADream. Then mn DREAM.EXE. IFsas simple as that. Compile theFAADl package; - Go to the directory C:\vcprojects\faad2\lihfaad and double- click on libfaadl&su (if Visual Studio is correctly installed the Visual C++ IDE will now open). -In the IDE. select ‘Build/Set Active Configuration’ and in the window that appears select libfaad - Win32 Release’, and then click ‘GKL - In die IDE, select Build Rebuild AH'. Compilation begins, and should complete with 43 warnings, but no errors. -Now. go to the directory C : \ vc proj ects\faad 2 I i b land \Re le as e and c opy 1 i b l and Jib into the directory C:\vcprojects\drm\libs. Likewise, copy faad.h from c:\vcprojects\faad2\inclnde into the directory C:\vcprojects\drm\libs. Build the QT MOC tiles: - Go to the directory C:\vcprojccts\drtn\wmdows and double- click on MocGLT.bat to launch it. A number of files will automatically be created in the directory C:\vcp roj ee ts\d rm\ window s\nioc. Compile DREAM: - Go to the directory C:\veprojects\dmi\windows and double- click on EDRM,dsw (if Visual Studio is correct I v installed the Visual C++ IDE will now open ). - In the IDE. select *Build/Sci Active Configuration’ and in the v, indow that appears select ‘FORM - Win32 Release*, and then click OK\ - In the IDE. select 'Build/Rebuild ALL. Compilation begins, and should complete with one linker warning, but no errors. Run DREAM: - Go to the directory C:\veprojects\dnn\wmdows\Rdeuse. Copy DREAM.EXE from here to a new ly -created directory C ^Program FiiesVDreanu Results A click on DREAM.EXE stuns the program. Once the receiver has been tuned to n suitable frequency, an audio sig- nal will be produced after a shon delay. Hie station being received and transmission information will be displayed on the screen < Figure 2 l Further information is available under ‘ View/Evaluation Dialogue’. This mode (Figure 3) shows the DRM spectrum and a large quantity of additional information including the current signal-to-noise ratio I SNR), die bandwidth, and the operating mode. It is also possible to experiment with a range of software options. A broken red line indicates ihe measured centre frequency of the DRM signal, which simplifies cali- brating the receiver. DREAM is not restricted to a 12 kHz fre- Vsfca Fedfo t r Parpen preamj * 1: SHEiatl fl# I c^m; " '“J-j; : j LldmJTC 3CT ■ r liQQi lfV3'Pj -20 -' Hi -tj - - • => fcfl I'C Stans (i f sp 5 dried t V: RTL DRM Sit R3te:20j9G Kbps EEPI ID. 7001 A - L2&Q4 - elektsr ebdmnio Figure 2. DREAM receiving RTl DRM 4 35 Figure 3, The DREAM evaluation dialogue displays the most important parameters. quencv hand, but rather accepts the entire input band between 0 kHz and 24 kHz. This relaxes the constraints on the receiver and allows die receiver lo he detuned by a few kilohertz, for example to avoid an unwanted interfering carrier on she image frequency, AM reception The receiver option Settings/Receiver mode/AM (analogue t allows DREAM to receive amplitude-modulated signals from normal AM broadcasters. DREAM looks for a strong carrier in the input spectrum and subtracts its frequency from the upper sideband of the received signal. The receiver thus oper- ates as a single sideband i SSBl receiver. This allows both SSB. CW and utility signals such as weather fax and RTTY to be decoded. In order to receive an AM station, first ensure that the fre- quency band to be received sits in the middle of the 111 ter Figure 4 . In confrosf to the DRM software radio , DREAA\ eon also demodulate norma/ AA1 fra n; missions on rfie PC fOi FAJU_V||? UOTTf? : -lUKT- TM »=xnrrj -j wz: ““ z Site 3 - ’■ EfiE. r Lre*i B ► ■ h m ■ 2 SCfr’TfrSDT? !jt=L UTCt. ■ 4 - r ,JTr“ ^ — J -T Z; rea 1 - CT -TiE ■ 1 . “ J 1 IfcH-JflTSsa; '■‘.J; -jS. 7cm ' r;'airs JZ “E" r tar =7 : "‘ l :- :j ■ ds : - Tn-iV".-' - -ij ? : r ■ 5*C ME-1 . ViSTf! Zearch for the AM station: the carrier should stand out death from the spectrum at 1 2 kHz. Then switch to AM mode. In the evalua- tion dialogue the broken red line asain indicates the detected 1 -i— carrier frequency at around 12 kHz. This Netting remains fixed as lon^i as AM mode is active. The receiver can therefore he reiuned freely to brine in other stations. — ■*- The single sideband demodulation process gives a number of advantages over the conventional envelope detector. Selective fading normal h causes sev ere distortion if the carrier is sie- •v w ■ — mlieantlv attenuated. DREAM, however, can offer trouble- free reception in these conditions, although the sound quality may van slightly. Also. DREAM includes a very good low- pass flier. The input signal is analysed by an PET, the upper sideband moved down to zero frequency, and then the audio sig nal re-svnthcsjscd bv an inverse FFT covering the band from ■ ■> U kHz to 5 kHz. When the result compared with a conven- tional short-w ave radio tuned to the same frequency', the delay introduced by the digital processing and data buffering i> dearly apparent. Single-sideband lSSB ) reception also offers the possibility of obtaining better reception from severely distorted AM sta- tions, Since short-wave broadcast channels are at multiples of 5 kHz, it is often the case ill at there are pairs of stations just 5 kHz apart: the upper sideband of one then completely ov er- laps the lower sideband of the other. With DREAM it is possi- ble to receive only the undistorted sideband. In some cases this will mean inverting die input spectrum t option 'Flip Input Spectrum' in the evaluation dialogue). This is also required in order to receive an SSB transmission usin^ the lower ride- band. When the Ekktor Electronics DRM receiver is brine w used, line adjustment of its intermediate frequency is possible using the program DRM. EXE. Reception results are better than when using direct conv ersion, rince the software com- pletely discards (he unwanted sideband. Conclusions DREAM_Y1.0 is certainly a serious alternative to the DRM Software Radio. The program k absolutely stable in use and requires less processor power than the earlier versions. It is possible to receive images, and the program can create a log file with reception results. As already noted. DREAM is very tolerant of the position of the DRM baseband signal within its input bandwidth, scanning the entire range from 0 kHz to 24 kHz. It also offers an analogue AM reception mode, allow- ing it to be used w ith the Ekktor Electronics DRM receiver for standard broadcasts. ...... . 36 eIs'sIoi elitfio'ie - 4/2004 ELEKTOR ELECTRONICS IS STAGING ITS FIRST SEMINAR FOR ELECTRONIC PROFESSIONALS THE FUTURE OF THE MICROELECTRONICS IND USTRY IN EUROPE Starr o f a boom QL inerelx a blip. Electronics guru Peter Kember makes this sround-breaki n s address O W Plus CAN control area networking. The LPC2 1 00 - the new family 32-bit microcontroller Datalossins and sensors Low power radio solutions All from the industry's leading experts gathered together on one day - at Warwick University, Coventry M AY 7 For further details and to book your place contact: PRB Public Relations and Marketing, 3, Crescent Terrace Cheltenham GL50 3 PE Tel: 01242 51070 Fax: 01242 226626 Email: bernardhubbard@prb-marketing.com Extensive I/O:- Serial, rDA, SPI, PC, Analogue, imers/Counters, RTC, etc. • Large Memory Capacity: Flash, SRAM, DRAM. J •Supports;- . ijyione & Colour LCD's, PToucnPanels & Keypads, w Very Low Power. “ *t ■ Target easily & quickly. ' ( # / £3 oil ANSI ‘C’ compiler, assemble lfinker all Windows32 v based. ‘^•Source Level Debug. ■ full Driver Support with H ; Libraries. jfeaiTime Multitasking OS with S free run time licence. -ptE Unlimited email support. I 1 lay III M > 1 www. cms. uk. com see our web site for full details CAMBRIDGE MICROPROCESSOR SYSTEMS LTD Unit 17-18 Zone 'D' Chelmsford RcL Ind Est Great Dunmow, Essex CM 6 1XG Telephone: 01371 875644 email: sales@cmscuk.com 4 2004 Eiektor Electronics start here Repairing the damage caused by leaking batteries Most or you will have suffered from this at one time or another: a torch or other battery-powered equipment has been neglected tco long and the batteries started leaking* After all, these cells can* rain a cocktail of corrosive chem- icals that will eventually rind their way through the battery housing and end up in all those places w n ere th ey re n o t wo n re d , NiCad cells that are over- charged con vent the elec- trolyte in gas Form* The metal parts in particular will be dam- aged by this, with disastrous consequences. It becomes even worse when the batteries, whether in a holder or not r are mounted on a PCB. This con be the case with (older) microprocessor boards, which have, For example, a real-time dock that has to keep running, or a volatile memory that stores settings that have to be main- tained when the power is turned off or lost. A leaking battery on □ PCB leads fo corrosion, which has both visible and invisible consequences. When repairing this it is point- less just to palish those areas that ore visibly affected: any repair has fo stand the tests of time. The electrolyte can penetrate into cer- tain materials and continue with its destructive process under- neath the surface, just cleaning the surface is therefore not enough; the only remedy is the complete removal of every bit of electrolyte. On a PCB the corrosion can be seen in various ways. Firstly as a simple mark where the bat- tery is mounted* Next, It can be seen os a green or white deposit on the pins, compo- nents and solder Joints, We start with the removal of all components that are on the affected part of the PCB* Use a good quality solder sucker and/or desoldering braid and keep in mind that in many cases, such as for resistors, capacitors, 1C sockets and standard logic ICs, the PCB is more important than the component that has to be removed. In those cases, you can cut the connections and remove them one by ane. One problem that occurs when desoldering is that solder affected by corrosion often won t flow properly. In that cose you should odd some fresh solder and try it again If you are still unsuccessful, you should sand the joint until the corrosion has gone, and fry again with the sol- der sucker. In extreme cases you may hove to use a PCB drill to restore the connections. When all components hove been removed from the corroded part of the PCB, it should be sanded with fine wet-and-dry sandpaper. Any solder resist should be removed as well; you just keep sanding until all tracks become shiny again. To finish the job properly any remaining electrolyte has to be neutralised by rinsing the PCB in □ 1:1 mixture of water and vine- gar. Et is often thought that oil batteries contain acids, but Nrcads and alkaline cells have KQH os electrolyte, which is an alkaline. Hence we need to use an acidic solution to neutralise it. After this it should be rinsed with water, dried and then cleaned with alcohol (white spirit is much cheaper, but less pure]. The PCB should then be sprayed with a solder lacquer, which protects the tracks from oxidation and lets the solder flow cleanly when the FCB is repopulated. The PCB now has to be inspected carefully, and any bro- ken tracks have to be repaired using enamelled copper wire, cur to length. The components can then be soldered back onto the PCB, It's quite a time-consuming job, but if if is dene properly the PCB should give many years more service, unless the batteries start leaking again,*. 38 ekktor dwtronio ■ 4/20 M Through-hole plating 7 double-sided PCBs Making a double-sided PCB is far from easy. It is quite o task to make sure that the artwork films with the tracks and pads are per- fectly aligned on both sides. And it becomes even more difficult when both sides hove to be con- nected at various paints. The professional PCB manufac- turer uses through-hole plating: the board is drilled and a thin layer of copper is deposited in the holes that require o connec- tion between the top and bottom side. An electrochemical process is then used to moke the actual connection. This however requires specialist equipment which won't be available in many electronics labs. Fortu- nately there are other methods r although they ore somewhat laborious. These methods ore also useful 'when repairing dam- aged double-sided boards. The simplest solution is to solder the pins or leads of the compo- nents on both sides of the board. This is easily accomplished with conventional components (resis- tors, diodes, transistors, etc.], but with radial capacitors and ICs (in sockets] this is more difficult. The second method uses Litz wire, which is often on hand in the electronics workshop. This wire consists of many thin cop- per strands, "which are highly suitable for making connections between two sides of the board and still leave enough room in ihe hales for the component leads [Figure 3). The thin strands are soldered on the com- poneni side of ihe board, taking care that the solder joint doesn't rise above the boord too much, and that the hole doesn't become blocked by the solder. When all connections have been made, the components con be placed on the board and sol- dered on the solder-side. We recommend that you use two strands per connection, ihereby reducing the risk that a connec- tion is damaged when the com- ponent pin is stuck through the board. For DIL-IC sockets th ere is a much simpler method: there are contact strips that have the same type of contacts as turned-pin 1C sockets. These have the advan- tage that they are raised slightly further above the beard, provid- ing enough room to solder the pins on both sides of ihe board (Figure 4]. These strips ore preferable to ordinary turned-pin sockets because the pins on the component side of the board are easier to get to with a soldering iron from both sides. 4_::e: Alternatives for battery-backed RAM Many microprocessor boards include a static RAM that stores o variety of system settings. If is often desirable to keep these set- tings when the power supply is turned off or interrupted. For this reason a backup battery es mounted on these boards, which provides standby power to the SRAM. At first sight, th is seems a simple solution, but it is far from idea! Batteries take up □ fair amount of space on the PCB. They also need to be checked regularly for any passible leakage and that they supply the correct voltage. On modern processor boards o flash memory or EEPROM is often used, neither of which require a backup battery. Older boards can be given a new lease of life by replacing ihe SRAM and batteries with a mod- ern alternative such as FRAM r Ramtran international Corpora- tion has introduced two ICs, the FM1608 and FMl 808, which ore Idea! for removing the need for backup batteries in older sys- tems, and which are or course very useful in new designs too. These ore a special type oF non- volatile memory. Ferroelectric RAM f which is being developed further by the manufacturer. A detailed description of the tech- nology can be found on the ir website at wwsv.romtron.com/aboutfram. The manufacturer guarantees ot least 10 billion read/ write cycles and a 1 0-year data retention Far these ECs. The best characteristic of these memories is that they □ re pin compatible with stan- dard 8 K x 8 [FMl 608) and 32 K x 8 (FMl 808] SRAMs and E EPROMs, and can therefore be used in existing designs without having to make any drastic mod- ifications. There is just one aspect of the design ihol has to be taken into account when a 'normal SRAM 4/2M4 - dektor drtfror.ia 39 start here FRA?it Valkl h femo/y Rea d Refa ti on ship Signaling - s / \ r ~ D5a ( 01 ) 1 m ? — FRAU SignaKrig Invalid Memory Reed Relationship ce \ Ad*3r=ss — ^ E-y j A1 - >- X X 01 X M ) — c*saa - x-i ysre-'i is repfaced by an PRAM: the CE- signal of an PRAM is used to dock on internal address latch, as shown in the timing diagram. This means that the SC requires a falling edge on this pin after a valid address has been put on the address bus, otherwise fhe address won't be recognised \ . .4 - is : Temperature switches in SOT packages The MAX 6 5 09 and MAX65 1 0 made by Maxim are very small temperature switches, which can be configured with □ single external resistor to trip at any temperature between -40X and + 1 25'C The accuracy of the trip point is typically -0.5'C and ±4.7" C maximum. They have a pin that sets the hysteresis to either 2X or 10X. The MAX6509 has an open- drain output. The MAX6510 uses the OUTSET pin to choose between on output that is active high, active low, or an open- drain with o pull-up resistor. The output could for example drive a reset or interrupt to a microcon- troller system, switch a supply or activate on external alarm. The current through these compo- nents should be kept as small os possible, to limit any temperature variation due to Internal dissipa- tion. With these components you should pay particular attention to the suffix [the letters immediately fol- lowing the part number) and specifically the first letter! An H -type ( Hof ) switches the output when a rising temperature exceeds the trip point and switches back when the tempero ture falls below the trip point, minus the hysteresis. A C -type ('Cold ) in contrast will switch when the temperature falls below the trip point and switches back when it rises above the trip point plus the hysteresis. In other words: the hysteresis is either above or below the trip point, depending on the type of sensor. By combining both types in one design it is very simple to moni- tor a temperature between lower and upper limits. Two possible configurations are shown in Fig- ure 6. The lower circuit uses the open-drain outputs of the MAX65Q9 as a wired-QR, with a common pull-up resistor. All of the temperature switches in this example have a hysteresis of 2 C [input HYST connected to ground). When the trip temperature has been chosen, the corresponding value for R. pf can be read from one of the graphs In Figure 7. For an exact value, one of the following formulae should be used. fst v5h tsv f £.-.attl ■ : For temperatures between -40X and 0 C use: R se j - [{1.3258 x 105) / [T+1,3J] - 310.1693 - [{5.7797 x 105 ) / t + 1 . 3 ) 2 ] For temperatures between OX and +1 25'C use: R sel - [(8.3793 x 10 4 ) / T] - 21 1.3569 + [(1.2989 x W) / T 2 1 where I is in K, R se , is in fen. From fhe graphs you con deter- mine that the switches in the examples have trip points at about 0 C (R : ^ f = 100 kO) and 65 X (R^ - 30 kO). WY ]5-4 SSTT ffi . TEMPERATE fl* = 5 C TD -V-12S O 21 C- ffi ffi S iEuitfiX'USi C | cas-a 40 eieklcr e!ectrc“>s -4/2004 n transistors^ 1 Crystal — sal's it! Poor Men's ORM is here Burkhard Kainka Almost too good to be true but tried & tested: a totally undemanding receiver giving you an opportunity to experience DRM digital broadcasts on shortwave. Digital SW almost for free! Th ere are □ large number of shortwave stations broadcasting not only conventional analogue signals but also digital pro- gramme material. This raises the exciting question if there might be stations that rif standard quartz crystal frequencies and so can be captured using the ultra-simple receiver presented in this short article. Ultra-simple? Yes. the receiver consists of noth- ing more than a direct mixer and a crystal oscillator. As you could have surmised there are off the shelf crystals that fit the bill {else th ere would not have been an article]. Three shortwave frequencies used by Deutsche Welle [German world service), 3995 kHz, 6130 kHz and 6140 kHz match the com- mon microprocessor quartz crys- tal frequencies of 4.000 MHz and 6.1 44 MHz — that is, with a trick! In each case, the oscilla- tor should run about 2 kHz above the nominal crystal fre- quency. In many cases, a crystal frequency can be 'pulled □ little by using a load capacitance which Is slightly larger than the usual 20 to 30 pF [assuming the crystal operates at Fundamental resonance). In our circuit a series capacitor of 12 pF does the job, forcing the crystal to resonate a little above its nominal fre- quency. It Is nor terribly impor- tant if the actual frequency Is 4002 kHz or 6146 kHz. Inside the receiver the digitally modulated signal received at the DRM station frequency is mixed down Into the audio range. This simple operation causes the DRM baseband (which is slid digitally modulated) to appear at 7 kHz for the station frequen- cies 3995 kHz and 6140 kHz, or 17 kHz for the transmitter at 6130 kHz. Decoding these sig- nals an the PC will only succeed if you use the DREAM software far DRM, because this program is tolerant of Input irequencles between 0 and 24 kHz, Luckily, DREAM Is on open-source pro- gram hence does not incur any costs. It should be noted that the received DRM baseband will need spectrum-inversion. This is because high-side Injection is used, that is, the loco! oscillator operates at a frequency above the station frequency. In the pro- gram, activate the 'Flip Input Spectrum option. Oscillator and mixer From a point of view of modern electronics the lower ports of the shortwave bonds can hardly be colled 'high frequency'. Conse- quently mere are no problems building the receiver from AF / fast switching transistors like the ubiquitous BC548C or BC549C Th e oscillator arouno I i feeds its output signal directly onto the emitter of mixer transistor T2. Mixing takes place on the curved port of the Transistor char- acteristic. The base gets the RF signal directly from o heavily damped hence wideband input circuit that's tuned for maximum RF with the aid of a trimmer. The upshot is that the DRM base- band is available at the collec- tor. Depending on the available level, the DRM signal coupled out via C5 is fed fo the Line or Microphone input of your sound- card for processing by the DREAM soffwa re. Und er favourable circumstances (including propagation and the absence of man-made noise] , an indoor wire antenna of about 3 metres will be sufficient. Better results are achieved with an out- door antenna of about 10 m. The Deutsche Welle (DW) trans- mitters put up usable signal strengths across most of Western Europe. However, if DREAM starts to indicate o poor signol/noise (5/Nj ratio (less than 15 dBj look for wideband noise as a cause for signal cor- ruption. Under good conditions, our little receiver supplies an S/N greater than 20 dB. The DRM broadcast schedule on DW may be gleaned from, among others, Stefan Mohn's website at w\vw_drm/ irtfo.de 1-4 jl 7.-1 4/2004 - diktur heiress 41 (without obligation) for just' £ 7.50! Try out the new elektor electronics and get the next 3 issues (May, June and the July/August 2004 double issue) delivered at your doorstep. YOUR SAVING: MORE THAN 41%! The trial subscription expires automatically. Fill out the reply card with this issue. Burkhard Kainka Aerials and preselectors for wave or wire is someth in I he UHF band, radio waves propagate essentially in a Iine- of-sight manner* similar to light, and this limits their recep- tion to a range of around 1 00 km, depending on aerial height. However* radio waves at frequencies below 30 MHz show completely different behaviour, which makes a significantly larger reception range possible. Of course, die complex prop- agation mechanisms in this frequency range also lead to spe- cial problems, such as dependence on tire time of day, field strength fluctuations (fading) and selective fading. The decisive role in the propagation of radio waves in the short-wave bands is played the ionosphere, a set of weakly conductive layers in the atmosphere at great height that are formed by solar ionization. The ionosphere results from colli- sions between particle radiation and gamma radiation from the sun and air molecules* which become ionized with the release of electrons. Within certain frequency bands and at certain incident angles, the free electrons generated in this manner act like a mirror. At large incident angles and high frequencies, the ionosphere is instead transparent. A short-wave transmitter can be received in the nearby region via ground-wave propagation over a range of only around 30 to 100 km, depending on the height of the aerial. At greater distances, the transmitter disappears behind the horizon due to the curvature of the earth, making a direct link impossible. However* radio waves reflected from the iono- sphere can reach receivers located in a region starting at cer- tain minimum distance away for the transmitter, as illustrated in Figure I. Between the limit of reception of the ground wave and the start ol reception of the reflected signal, there is a region called the "skip zone" where the signal cannot be received. The reflection angle that would be nec- essary for the signal to be received in this region is too large. Of course, the trans- mitter also radiates energy at this angle, but it leaves the atmos- phere without being used, per- haps to be received some- time later on by one of our neighbours in outer space. The minimum dis- v \ Receiver V. \ \ \ Figure L Signal reflection and the skip zone for propagation m the short-wave hands. lance between the transmitter and the receiver v*uks with the time of day for each frequency, and it also depends on the level of solar activity, which varies over time. High frequencies can only- be reflected at very shallow angles. Consequently, the ground distance spanned by the reflected signal is generally greater in the higher- frequency' bands* The skip zone is also correspondingly larger: during the day it ranges up to aronnd 200 km at 6 MHz and around 1000 km at 1 5 MHz. The skip zone expands at nig lit, and with it the reception range. Asa result, it often happens that a particular transmit- ter can fee initially received quite well near dusk but then sud- denly disappears, since in a manner of speaking it has slid into the skip zone. If the same programme is also being broadcast on other frequency bands fas is customary' with BBC, DW, etc.), it is recommended to change to a lower fre- quency when this happens. Generally speaking* radio waves arrive at a receiver via more than one path. The differences in the path lengths give rise to phase differences, which lead to partial reinforcement or can- cellation of the waves. Especially in the short- wave band* rapid fluctuations in field strength are common. This fre- quently' causes selective fading, which is particularly notice- able with AM transmitters in the form of unpleasant distortion resulting from nearly total loss of the carrier signal, causing it to be overshadowed |y the sidebands. DRM (the new digital transmission technique) is also affected by this fading, but the modulation and coding methods used for DRM are especially robust and can tolerate partial loss of data. Thanks to effective error handling, even deep dropouts in the DRM spectrum* such as those caused by cancellation at certain frequencies* generally do not interfere with reception* DRM restores excitement to radio listening oil the medium- and short-wave bands. There are already quite a few stations available (see Table 1)* and new transmitters are constantly being added to the list. A longish wire Strong short-wave transmitters can be received using ail 'aer- ial system 1 (rod aerial or piece of wire) with a length of less than a metre. For long-distance reception, it is naturally much better to use a ’longish’ wire aerial, which preferably should be strung up outdoors - as widely separated from other objects as possible, as high as possible and sufficiently far away from the house, in order to avoid the "noise cloud' ema- nating from the house. In theory, a wire aerial has a resonant frequency at one quar- ter of the signal wavelength, although a good earth connec- tion acting as a counterpoise is important for this. In practice, wire aerials with lengths of around 10 metres have proved to be satisfactory. [f the receiver is located close to a window or the outside wall of the house, it is sufficient to connect the end of the wire directly to the inner contact of the aerial socket. However, if the distance between the aerial and the receiver inside the house is relatively long, the connection should be made using coaxial cable* with the opposite pole being provided by an earth connection close to the feed point of the aerial (see Fig- ure 2 ). Here it makes no difference whether you use 5QT2 cable or 75-£2 cable. After all* the base resistance of the aerial varies with frequency, and it has a complex impedance with 45 Figure 2. An outdoor wire aerial connected via a coaxial cable. Figure 3. A freely tuneable resonant circuit used for preselection. Figure 4, Tuning using a variable- capacitance diode in stead of a rotary variable capacitor Rx Rx Figure 5. Tuning from 3 MHz to 30 MHz using a dual variable capacitor. alternating capacitive and inductive components. The coaxial cable also has its own resonances, since it is not being used at its characteristic impedance, and it transforms the aerial impedance, with the net result that resonances other than those to be expected from the length of the aerial can also occur. However, this does not have much of a noticeable effect at the receiver, since signal level variations of around ■w 10 dB hardlv matter with DRM. Outdoor wire aerials are normal! \ made from stranded wire ■■ with a sufficiently large cross-sectional area, in order to obtain good mechanical strength as well as low ohmic losses, A lead from a standard mains cable or loudspeaker cable \\ ith a cross-sectional area of 0.75 to 1.5 mm_ is suitable for this purpose. It is also possible to use significantly thinner wire. A lest using 10 m of thin magnet v, ire (03 mm diameter) yielded usable results for DRM reception, and it has the advantage of being quite inconspicuous. If v ou shv away from constructing vour own aerial, in mum cases you can make use of existing systems or cables. A typi- cal aerial system provides not only television and UHF sig- nals, but also the entire AM range from long-wave to short- wave, It's certainly worth trying. m wr i— In many cases, better results can be obtained with a rooftop aerial than with an indoor aerial. Old rooftop aerials are often no longer in use. but the aerial cables leading to the roof are still in place. The cable by itself can also be useful. Such a ■forgotten' aerial cable that has been converted into a 'sinirie lead', which means with the inner conductor and the screen shorted together, forms a usable vertical aerial. The cable usu- ally runs all the way to the roof of the building and thus reaches a greater height than a horizontally strung wire aerial. %_ %_r ■# '6— Especially at relatively high frequencies (above 15 MHz), bet- ter results can be achieved using such an aerial than with an outdoor wire aerial. Preselection A Tongish" wire aerial has a broadband characteristic and receives the entire AM radio band between 0.5 MHz and 22 MH? relatively uniformly, so no additional tuning is need for the aerial itself. However, preselection is worthwhile if reception is degraded by mirror frequencies. Practically every receiver that works on the superset principle has two reception frequencies: the intended frequency and the mirror frequency , which is separated from the intended fre- quency by twice the intermediate frequency. W ith the usual IF of 455 kHz (as used in the DRM receiver published in the March 2004 issue ), this means the mirror frequency is located 910 kHz above the tuned frequency. For receivers having a switching mixer ( such as the diode-ring mixer of the DRM receiver), the received signal is mixed with not only the fun- damental frequency of the oscillator signal, but also (with a certain amount of attenuation i with all odd harmonics of the fundamental oscillator frequency. Primarily in case of recep- tion in the medium-wave band, this can lead to interference from mixer products formed by harmonics of the mixer oscil- lator and strong short-wave signals. Consequently, a medium- wave preselector often pres ides significant improvement. A preselector connected between die aerial and the receiver ri most commonly used, and such preselectors are generally tuneable. Suitable preselectors are available from specialist t amateur] radio shops, but you can also build your own. 46 efeJticr^ctrenio-AiflCl Tuneaib/e The snmdard approach to building a preselector is to use a tuneable resonant circuit {Figure 3), the coil can be wound as an air-core coil, which means without using an actual core. The wire diameter k not all that important for such air-core coils. For small coils* you can use enamelled cop- per wire w ilh a diameter of 0.3 to 0.7 nun; somewhat heav- ier wire should be used for larger coils for the sake of mechanical stability. A coil having a diameter of 8 mm and 20 turns over a length ol 10 mm has an inductance of 2.5 uH. In combination with a - 70-pF variable capacitor, it has a lower resonant frequency oi approximately 5 MHz. This circuit can thus be tuned across the 49-m band and the higher-frequency bands up to around 16 MHz. A tap at the second turn provides the proper impedance for connection to the receiver. The aerial can be connected using a coupling coil with two to iour turns. It y ou make the coupling coil such that it can be moved back and ionh, the degree oi coupling can be adjusted. \ou can then experimentally determine the best adjustment. 1 ighter coupling yields a higher signal voltage, but it decreases the Q factor of the resonant circuit and thus reduces the attenuation at the mirror frequency. If it is necessary to use a short aerial (such as a rod aerial), the coupling must be designed to he relatively tight . In this case, the aerial can be connected directly to the hoi end of the resonant circuit. The resonant circuit shown in the figure has a high Q factor f typically 50). This yields a bandw idth of 120 kHz at 6 MHz. As a result, the variable capacitor must be tuned relatively precisely. For DRM reception, the optimum tuning can be recognised by a maximum signal level in the spectrum dis- play generated by DRM software, but the delay in processing the date tor this display makes adjustment difficult, [t is easier to use direct acoustic monitoring by connecting the receiver output directly to the Line In socket of the sound card, Ifis then easy to time for maximum noise volume for the DRM transmitter using the speakers of the PC. If the preselector is built into an enclosure, the most important frequencies should be marked on a scale. Figure 4 shows the vjme type of resonant circuit with the rotary variable capacitor replaced by a high-value variable- capacitance diode, such as the type BBJ 12 (available from Geist Electronic). Here it is important to use a stable, well- filtered voltage for the tuning potentiometer, since other- wise reception can be degraded by phase modulation of the aerial sinnaL The tuning range of a simple resonant circuit does not exceed 1 :3 with a standard variable capacitor. One solution is to use several coils that can be selected using a rotary switch. Another approach is used by radio amateurs, who are faced with the same problem in the standard amateur radio bands (80 m to 10 m. which corresponds to 3.5—29,7 MHz i Tins requires a preselector with a tuning range of 1:10. The solu- tion is to use coupled circuits with two fundamentally differ- ent resonant frequencies. Figure 5 shows a proven circuit using a dual variable capacitor and a second coil with 10 turns. Although there are two ’bad' pass frequencies for every 7 setting, they are well separated trom the mirror frequency of the receiver. Good air- dielectric variable capacitors are no longer easv to come by. It k often possible to scavenge them from old Table 1 DRM transmitters and frequencies * Voice of Russia Time Frequency Station Language 06.00-24.00 Tu-Su 6095 RTL various 08.00-14.00 daily 1 5440 DW English 10,00-12.00 daily 6140 DW English 30.00-1 2.00 daily 9850 RNW" English 10.00-15.00 daily 7320 BBCWS English 11.00-13.00 Sa & 5u 9410 BBCWS English [72.00-1 2.57 daily 9850 RNW”’ Dutch 12.00-13.00 daily 6140 DW German 13.00-15.00 Mo-Fr 9410 BBCWS English 14.00-1 5.59 daily 6130 DW German 15.00-16.00 daily 9490 VoR* English 1 6.00-1 7.00 daily 9490 VoR- German 16.00-17.29 daily 3995 DW German 36.00-18.00 daily 6140 ow English 16,00-19.15 daily 1296 BBCWS English 3 7.00-1 8. CO daily 9490 VoR* French 18.00-19.00 • ' • |? daily 6U0 DW German 1 9.0CH20.0G daily 11925 BBC Russian — — r 21 .CO-22.55 daily 11730 RNW" Dutch 2 U 5-24.00 daily 1296 BBCWS English “ Radio Netherlands World Service (Wereldomroep) 4/2004 - ehkfcf eiedrania 47 Figure 6. A '296- kHz aerial filter ant, Q- L 2 YYYYV IDiJrlH I 05 2 A Z CS dF la Op ♦ -O r * C3 063065 - 2 - 13 Figure 7. Using o cerorrr/c IF filter far preselection Figure 8. A magnetic-loop aerial. Figure 9. A funed era screened bap aerial made tram ZQOxiai cable. £flL CSSS 3 H radios. One source of suitable multi-gang variable capaci- tors from current production is Geist Electronic < www.geist-electronic.de). Fixed-frequency An alternative to a circuit with adjustable tuning is to use a fixed- frequency f Iter. In the medium-wave band, there is often only one usable reception frequency Although the rela- tive bandw idth of the input circuit is relatively large, good -deeds in is possible thanks to the low frequency A circuit such as that shown in Figure 6 can thus manage with a fixed inductor. This fixed-frequency filter for 1296 kHz improves reception of die BBC transmitter in the evening hours. It pri- marily reduces interference from multiples of the oscillator frequency in the short-wave bauds. For the 49-rn band, a quite simple solution is possible using the type SFE 6 ceramic IF filter, which is used for the sound IF in television sets. Figure 7 show s how, to connect the filter to the receiver input so it can be switched in or out as neces- sary The specified 3- dB bandwidth of around 100 kHz. v, Inch is actually too narrow , is broadened by die low imped- ances of die aerial and receiver to such an extent diat the measured 6-dB comer frequencies are located at 5850 kHz and 6150 kHz. In practice, this filter is primarily useful in the 49-m band when interference occurs from strong transmitters in the 40- m band. At 7 MHz. die filter prov ides an attenuation of around 40 dB. Magnetic-field aerials A Tongish’ wire aerial receives electrical energv from both the electrical and magnetic components of the radio w aves. By contrast, short aerials such as rod aerials predominant! y receive energy from the electrical component. This results in a higher lev el of interference, especially Inside a building. The coupling between the receiver aerial and electrical equ ip- mem or the mains wiring is primarily capacitive. Better results can thus be obtained bs receiving the magnetic-field compo- nent. ht principle, ah that is necessan for this is a u ire loop or a coil. Com mo n K used solutions are loop aerials w ith a few turns of w ire or single-winding loops, sometimes called mag- netic loops'. Tuned loops with high Q factors are particularly effective. For instance, you can use a length of copper pipe formed into a circle with a diameter of one metre. How ever, a broad piece of aluminium foil wound around a cardboard box with suitable dimensions also provides stood results. When connected to a variable capacitor v. ith a maximum capacitance of 500 pF. the loop forms a high-Q resonant cir- cuit and thus delivers a sicnificanlh higher aerial voltage than would be expected from an aerial of this size. The receiver should be loose! v coupled using a small coupling coil, in order to av oid excessively damping the resonant circuit (see Figure 8). The optimum size and position of the coupling coil is best determined experimentally. Due to the high Q factor of the aerial, an additional preselector is in any ca^e unnecessary A magnetic loop aerial can also be constructed using normal w ire, although this yields a lower Q factor and thus a lower aerial voltage, as well as a larger bundv, idlh. If it is necessary to make the aerial smaller, two or more turns of insulated wire can be used. An especially effective solution is an dec trie all) screened loop 48 ebJclw electronics - 4/700-1 aerial, vriiidi In its simplest form can be made from a length of coaxial cable. Such an aerial can be inconspicuouslv fitted in a bookshelf and it provides a relatively good signal to noise ratio. The resonant frequency depends on the size of the loop and the capacitor setting. If the total length of the coaxial cable is four metres, a resonant frequency range extending to below 6 MHz can be obtained with a 500-pF variable capacitor (see Figure 9). The primaiy inductance of the wideband trans- former should be greater than that of the wire loop. Good results can be obtained with 20 turns on a ferrite core or toroidal core. In the interest of obtaining a high Q factor, die tuned circuit should not be too heavily damped. Consequently, the secondary has only two to four turns. The best value for me coupling coil should be determined experimentally. In the medium- wave band, ferrite rod aerials ha\e Iona since proven their worth. Like magnetic loops, they are relatively insensitive to electrical interference. Figure 10 shows a fer- rite rod aerial followed by an impedance converter. With a 10- mm diameter ierrite rod, the coil requires 70 turns of stranded RF wire i iitz wire' i or 0.3-mm enamelled copper vv ire. Approximately 100 turns are necessan on a thinner rod ( S mm diameter). Rclatis elv large resonant voltages arise across the tuned cir- cuit. even with distant transmitters. For example, at the author > location in Essen, Germany, at peak reception times ferrite rod *5V -© TJ BF215 Cl HX . —ii » m 1G0n 350 _lH 030355 - 2 * 23 Figure 10. A ferrite red aerial with on impedance converter. an open-circuit voltage ol 50 mV can be measured across a ferrite rod aerial with a length of 20 cm for the BBC signal at 1296 kHz. At the low- impedance receiver input, this still amounts to 5 mV. which is more than enough steam for our new digital steam radio. ELEKTOR Hardware^ Software mnw The Flash Microcontroller Starter Kit costs just £ 69.00 / US$ 1 12.50 (plus postage). Step into the fascinating world of microcontrollers with the Elekfor Electronics Flash Microcontroller Starter Kit. Contents of Starter Kit 1 : Flash Microcontroller board (ready-assembled and tested PC 300-mA mains adapter Serial cable for COM port Software bundle on CD-ROM Article compilation on CD-ROM: • 89S8252 Flash Microcontroller Board (December 2001) • Microcontroller Basics Course parts 1 -6 [January through June 2002 • Microcontroller Basics FAQ (September 2002) • Port line and ADC Extension for 89S8252 Flash Micro Board [December 2002) • Chess Computer using the Flash Micro Board. Order now using the Order Form in the Readers Services section in this issue Eleklof Electronics (Publishing) • P.0. Bo* 190 • Tunbridge Wells TtJS 7WY " England, Telephone +94 (0) 1580 200 657 * Pax +44 (0) 1580 200 616 = - ts£lxxlc See also www,eIekfor- eIedronks,co,uk ~L[3^iV3a.lCu^£ TH£ ELECTS 0-N ICS 4 COMPUTES MAGAZINE - i4 - =:=>!:’ dedroato 49 Parallax BASIC Stamps - still the easy way to get your project up arid running! Serial Alphanumeric and Graphic Displays/ Mini-Terminals and Bezel kits Robotic models for both the beginner and the advanced hobbyist D MX Proloco i 11/ Sound Ranging Ansmatronics and Specialist Interface-Control Modules Quadra vox Sensorylnc Parallax ? lech-Tcols BASICMicro MP3 Sc Speech Systems Voice Recognition Ubicom Tool Kils j PIC & Rom Emulators PIC BASIC Compilers Development Tools Milford Instruments Limited Te! 01977 683665, Fox 01977 681465, sales@milinsf.com Dr DAO Output — Resistance ~y,&tage Light level Temperature S iop •" ■ : i_. m~r=- * - i.: =i. . - ■ 1 ^ — - ■V-S -j I m m low cast^under £60 • Built in sensors^or light, temperature and sound (level and waveforms) • Use DrDAQ to capture fast signals • Outputs for control experiments • Supplied with both PicoScope (oscilloscope) and PicoLog (data logging) software \ For more information on DrDAQ, please visit: 1 www.picotech.com/drdaq90 External sensors: Humidity Temperature 02 in Air Reed Switch • Scope and spectrum analyser functions • A fraction of the cost.of benchtop scope • Save multiple setups, for ease of use • Save, print and e-mail your traces • FREE technical support for life • FREE software and upgrades f • Automated measurements l Virtual JjisLrurtienf For more information on our scopes, please visit: J= ' . r '■ m www.picotech.com/Scope159 Tel: 01480 396395 Fax: 01480 396296 E-mail: sales@picotech.com 4 20D \ - cJfVlm e'ftfr&GiEs 51 Pandora's Sound & Music Box Recycle an old CI40M drive for ftoiggered) pQn^lacEx This project was originally conceived for model making applications as a cheap way to provide high quality audio playback in response to a trigger signal (typically from a pushbutton or FIR detector), but we're pretty sure Elektor readers can find many other uses. 52 &Lectriaiit5 - |/2uQ4 CU7MJT DELAY tKJtf'JT (ITLI^DJLTE Th:G:55?1 CV Figure 1 . The modern version of Pandora s Box is o black one governing triggered response from an old CD ROM drive playing back music or sound samples. >bu determine what 'horrors' (if any) lurk inside the box. The standard low cost solution to creat- ing auto-playback sounds is to use a record/playback chip (say, the ISD25XX senes) but these devices are limited to about 3 kHz audio bandwidth, not to mention a lot of hiss and noise, so the sound quality is not the best unless you're specifically after for voice mes- sages of the Stephen Hawking type. The Eiektor approach Over the past few years we have received many requests from readers asking for a circuit that would allow them to use an old CD-ROM player for the sole purpose of playing back music CDs, In many cases, that is possible just by connecting a power supply and headphones to your drive, inserting a CD and pressing the Play button. Sim- ple as this may sound, there me pit- falls, particularly with later CD-ROM drives that do not have a music play- back button. Also, we really could not stand the thought of being unable to select and skip tracks, etc. In true Eiektor fashion we wanted ro he in control of things and make the old CD- ROM drive do something really useful. The alternative approach developed by Ken Bromham and described in this article makes use of a 40-pin PIC 16F87X microcontroller which, helped by a small number of external compo- nents, provides a versatile controller module that will interface to any old ATARI CD-ROM drive- Mind you, ATAPI is not a brand, bur a connectiv- ity standard for 99% of all CD-ROM drives in PCs for home and office use Don't worry about it, just start rum- maging around in the attic or cellar, dig a CD drive out the IT skip at work, or commandeer the oldest (usually read- only) CD drive from the kiddies’ PC leaving a note saying "drive removed lor scientific purposes'. Never tell them you got the idea from Eiektor* instead, tell them to keep using the CD/RW drive which is much faster, better, etc. or better still buy them a mini MP3 player and headphones. 4/2Q04-e!Alef eledrenia 53 COMPONENTS LIST Figure 2. The printed circuit board is single-sided and contains seven wire links. Resistors: R1,R2,R6= lOkfl R3,R10.R1 1 ,H1 2 = ikn R4 - 3LQ3 R5 = 6LQ8 R7 = 22RQ R8 = 33ki3 R9 = oBkfl Capacitors: Cl r C2 = 47pF 16V radial What can it do? Tne controller module has two main modes of operation, single trigger use or multiple-trigger use, with further options selected by a 4-way DIL switch (pssL,. in fact both modes run simultaneously). There are also two digital switching outputs, asserted during playback, to allow other fea- tures (for example, lights or a motor) to be automatically switched on for the duration of the audio playback. Figure 3, When in doubt about ony constructional aspect , /usf use mis photograph for guidance . Single-trigger mode The function here is very simple. Acti- vating the single trigger input will cause playback of one track from the CD. There are four options {selected with a DIL switch), as follows : DIL switch # 1 off = normally open contact for single trigger on = normally closed contact for sin- gle trigger DIL switch # 2 off = no response to trigger until end of track on = respond anytime DU switch # 3 off = random track selection on = sequential track selection DIL switch # 4 off = keep disc continually spinning (defeat drive's inactivity timeout) on = allow the CD-ROM drive to power down. The latter options may require some elucidating. In the first case the play- back will always start almost immedi- ately as the disc is always spinning, but this may have some impact on the drive MTBF value (mean time between failure — you'll find it hard if not impossible to rind data on this). In the second case, if the disc has stopped spinning, there will be a short spin up f delay before playback starts. No prob- lem for applications that are likely to 54 ckfcl -:j rrEtlronio - 4/200-1 C3..C6,C9-C14 - lOQnF C7 r C8 = 22pF Semiconductors: DIALED, red, low current IC1 JC2-7812 IC3.IC4 = 7805 IC5 = PEC 1 6F6/ 1 /P, programmed, order code 030402-41 [see Readers Services page) Miscellaneous: S1-S8 = pushbutton, I moke contact spend a lot of time doing nothing'. There may be up to 24 tracks on the CD (the PIC chip is storing the table of con- tents data in its limited RAM). The mul- tiple trigger inputs should he left open. Multiple-trigger mode In this mode you can have a maximum of eight separate triggers (for instance, push buttons). Pressing burion 1 will always play track 1, button 2 will always play track 2. etc., up to and including track 8, It can be used with normally -open contacts only. If, for example, there ate only three tracks on the CD then pressing buttons 4-8 will have no effect. DIL switch 1 must be configured as normally open and the single trig- ger input left open. DIL switch 2 is not relevant. DEL switch 3 has the same function as above. DIL switch 4 has the same function as above. Digital switching outputs Pandora's Sound & Music Box has two digital outputs for control of external devices like sounders, lamps, ampli- fiers, signal routers, door locks, you name it, any thin g can be controlled as long as it has a simple 0/b V (TTL) dig- ital control input, or can be switched on and oh with a few mA of drive current. The “Output Immediate' output goes high immediately after triggering and remains high until end of playback. The other output called “Output Delay' goes high only after playback has started (that is, after any spirt-up delay) and rem ains high until end of playback. C/rcu/f and eonstrueti&n The circuit diagram shown in Figure 1 has few surprises, basically showing a microcontroller sitting between a S9 = 4-way DIF switch XI = 4 . 000M H z q u artea ysto i K s ,K2,K3 = 2-way PCS terminal block, lead pitch 5mm K4 = 40-way box header K5 = power supply p!ua far CD-ROM drive PCB ; order code 030402-1 [see Readers Services page) Heatsink,. e.g. r Fisher SK59 [6 fC/V/j Disk, PIC source and hex cede files, order code 030402-1 1 or Free Download CD-ROM drive Downloads PIC source and hex code files. File number: 030402-1 l.zip PCB layout in PDF format* File number: 030402-1. zip www»eIektor- elect ronics.co»uk/dl/dl.htm, select month of publication. bunch of switches and some connec- tors, The heart of the circuit is a 40 -pin PI016F871 microcontroller which fortu- nately has enough input /output pins to connect to all of the necessary ATA interface lines with enough left over to handle the trigger inputs, option selec- tions and the switching outputs. As can be seen from the schematic, only a handful of extra components are required. Note that the single trigger input RRQ (K3) and the option select inputs RB1-RB4 (S9) make use of inter- nal. that is, invisible, pull-up resistors. All other port lines of the PIC16F871 are connected to the drive’s IDE (ATARI) interface via connector K4. Together with R2, resistors R3-R9 pro- vide a simple potential divider network connected to input A0 on the PIC* Tne upshot is that a different voltage is applied to A0 depending on which but- ton is pressed (multiple -trigger mode). Tins voltage is read by an internal A/D converter. It is assumed here that it is not necessary to distinguish multiple simultaneous button presses. If multi- ple trigger mode is not required then resistors R3-RS and switches S2-S8 can be omitted* but R2 must be retained to keep inpur AO pulled, high. The PIC ticks at 4 MHz as determined by quartz crystal XI and its usual pair of small satellite capacitors, here iden- tified as C7 and C8. The user-defined settings are read from DDL switch S9. One LED* D1 P has been included to acts as a PIC awake’ indicator [very useful!). Capacitors C5 and 06, finally, ensure the 5-V supply voltage to the PIC remains as clean as possible. The circuit has been designed to oper- ate from a single 15- 18V DC supply, which should be “he aw/’ enough to also supply the drive's 12-V line. Two paral- leled 7805 fixed voltage regulators, IC3 and IC4 : provide -3-5 V for the PIC and the CD-ROM drive's 5 V line. The 12- volt supply is realised in a similar way by two 7812s in parallel. Alternatively, an old PC power supply can be used to power the CD-ROM drive directly. In this case it is recommended to retain the 7805s and use 12 V from the pc power supply for the controller board. A heatsink will still be necessary. Resistors RIO and Rll provide current limiting for the digital outputs and have been given the nominal value of 1 k£L The PIC chip can source/s ink an absolute maximum of 25 mA for each pin, so the value of these resistors can be changed so long as this maximum is not exceeded. In any case, it is suf- ficient to drive a transistor/ relay com- bination for example. The PCB shown in Figure 2 was designed for ease of use by yon. the constructor. It is available ready- made through onr Readers Services under number 030402-1. Alterna- tively, you may decide to make your own board using the artwork ole that can be downloaded free of charge from our website. As there are only regular components to fit on the board we doubt the con- struction will present any problems. The simplest and cheapest component on the board, however, is often the one that’s forgotten, causing major headaches and dozens of unnecessary emails of the 'Help it don’t woik T type! We’re talking about the infamous wire link. There are seven of them on the board and they are best fitted before any other component so they're not forgotten. Bolt the voltage regulators onto a common heatsink (see Figure 3 and the parts list), insulating washers are not required as all metal tabs are connected to ground. The PIC being the most expensive part, it deserves to be fitted into a 40-way DIL socket with good quality contacts. Although the circuit diagram suggests that there are rather a lot of wires and other things to connect to the board, Ln reality the situation is not that bad as you can see from Figure 4. Tne cables 4 2004 - dskt&r ckftranks 55 Figure 4. How to connect it all up. ■israz - T z Figure 5. Use /fits flowchart of the main program if you don't fancy reading assembly code but still want to understand how the software works. between the board and the CD-ROM drive . for example r are ready-made ones pulled from the junkbox or an old computer. Program The program that runs inside the PIC micro has been written in assembly language. The source code and hex file are available on floppy disk (anyone out there still using these?) or as free downloads from the Publishers' web- site. If you wish to program your own PIC, please feel free to do so using the files supplied. Alternatively a pre-pro- grammed PIC is available from Read- ers Services, the order code befog 030402-41. The source code supplied by Ken Bromham. is well worth studying, even if you do not build the project. Ken suc- ceeded in including plenty of com- ments so if you are familiar with this assembly language it should be possi- ble to follow the program, despite some classic spaghetti code. If not, you may still want to grasp the 'broader Lines' offered by the flowchart of the main program shown In Figure 5. The actual ATARI commands used by the PIC firmware are: PLAY AUDIO MSF (play from specified start to end location. MSF - Min- utes, Seconds, Frames, 75 Frames = 1 Second). READ TOC (get the table of contents). READ SUBCHANNEL (used to get the current audio status). SEEK [position the head at start of track 1, but will also cause the disc to spin up, so used to defeat the CD-ROM drive inactivity timeout), Tue READ SUBCHANNEL command is used at various points in the above sequence, whenever the program needs to know if playback is currently in progress or if playback has finished. Testing As usual, check for the presence of 5-V before inserting the PIC chip. The mod- ule can then be tested without con- necting to a CD-ROM drive. Simply power up and check that the LED on pin A4 flashes a few rimes. Nothing else will happen, but this confirms that the PIC is up and running. Switch off, connect to CD-ROM drive, power up. The LED should flash a few times and then continue to flash until a disc is inserted, the tray is dosed and the TOC (table of contents) successfully read. When the LED stops flashing, the mod- ule is ready to respond to a trigger and the different options can be experi- mented with. Noie that the CD-ROM drive must be configured as a MASTER device, and pin 1 on the PCB socket (£4) must go to pin 1 on the CD-ROM ATA interface socket (usually indicated by a red wire in the ribbon cable). When used with a single 12-V DC supply make sure this supply can provide a minimum of about 1.2 A., The audio output can be taken from the analogue out on the back or the CD-ROM drive or from the headphone jack a the front. To continue the low-cost theme, v/e recommend a cheap pair of active 'multimedia’ speakers (whatever that means), unless, of course, you really want to build your own amplifier! 56 dekf&i tSHfrenks - 4 2004 ATAPI protocol in brief ATARI (AT Attachment Packet Interface) devices use fhe same physical Interface as ATA [AT Attachment) devices such as a hard disk drive, so it is necessary to understand haw this works first In summary, the ATA device has a limited number of 8-bit registers (For example,, COMMAND, STATUS] and a single 16 bit DATA register. The interface is of the parallel type with 1 6 bi-directional data lines, where only the lower 8 data Sines are used for read- ing/ writing fhe 8 bit registers. ATARI devices use fhe same regis- ter set, although some registers have been renamed and serve a different function. Unfortunately this does not provide enough flexibility for the increased range of commands required, so the concept of a command packet was introduced along with a new ATA command, the 'ATARI packet command'. To send a com- rnand to an ATAPI device the general procedure is fo first write the (generic) ATAPI packet command to the device's COMMAND register, and then send the command packet by writing multiple times fo the device's DATA register. For CD-ROM drives the com- mand packet is 1 2 bytes in length and so 6 consecutive writes to the DATA register are required, sending 2 bytes each time. The command packet contains an opcode for the specific ATAPI com- mand along with any additional parameters that are required. Here is an example of the packet for the PLAY AUDIO MSF com- mand: Byte 0: Operation Code (0x47) Byte 1: Reserved Byte 2: Reserved Byte 3: Start Location Minutes Byte 4: Start Location Seconds Byte 5: Start Location Frames Byte 6: End Location Minutes Byte 7: End Location Seconds Byte 8: End Location Frames Byte 9; Reserved Byte 1 0: Reserved Byte 11: Reserved You can see that fhe command packet is padded with spare (reserved) bytes if necessary to give the 12-byte length. Detailed documentation can be Found on the web, www.il 3.org is a good place to start looking, just be prepared for some serious bed-time reading. ATA interface pinning Pin no. Lobel I HRESET 2 GHD 3 HD7 4 KD3 5 HD6 6 HD9 7 HD5 8 HD10 9 HD4 10 HDH II HD3 12 HD12 13 HD2 14 HDI3 15 HD! 16 HD14 17 HDD 18 HD15 19 GND 20 H/C 21 DMARG 22 GND 23 HWR 24 GND 25 HKD 26 GND 27 I0RDY 28 spsrwecsa 29 DMACK 30 GND 31 IHTRQ 32 [0CS16 33 HA1 34 FDIAG 35 KAO 36 KA2 37 CS1FX 33 CS3FX 39 DASP 40 GND Description Reset Ground Data bus bit 7 Data bus bit 8 Data bus bit 6 Data bus bit 9 Data bus brf 5 Data bus bit 10 Data bus bit 4 Data bus bit II Data bus bit 3 Data bus bit 12 Data bus bit 2 DqIce bus bit 13 Data bus bit 1 Data bus bit 14 Data bus bit D Data bus bit IS GHD Key pin DMA request Ground 1/0 write m 1/0 read Ground 1/0 channel ready Spindle sync or coble selecl DMA acknowledge Ground Enlerrupl request 16 BIT I/O Address bus bit l Passed diagnostics Address bus bit 0 Address bus bit 2 Chip select 0 Chip select 1 Drive uclrve/drive 1 present Ground fl. With compliments. Pandora 10X422-1 i There's only one limit to the applications of Pandora's Sound & Music Box: your imagination. Just couple the two notions Acme kind of trigger to 'an audible, pre-recorded response' and away you go. Here are some possible applications to get you going, In fairly random order: -a voice message system employing fhe public address sound equipment in a large building. Very useful for guiding the pub- lic to fire exits in case of an emergency, when written notices are hardly ever seen, let done rend. -an electronic dog barking in response to your doorbell; a track with More & Fiercer Dogs for really persistent callers that push the bell a second time (Pandora must have heard of Cerberus), gunfire for a third time, then police sirens, and so on. - a door- or doormat-triggered rnuzak or 'welcome' generator. - a voice guide in museums, triggered by visitors approaching an exhibit. - a low-cost jmgle-and-fune box for quizmasters and deejoys. -a language training aid. - a spoken Callsign / 'CQ Contest' generator for radio ama- teurs. For all of the above applications, you will need to bum your own music CD. Programs to compile music or sound samples onto our own CDs abound in PC land, CoolEdif being one of the best nown r Nate however that you can't use MP3 files just like that - a suitable decoder will have to be added. 4/20G4 -ele'itor dtdro ms 57 inside out Of Mice and Light increased accuracy without mechanics Harry Baggen These days, no one is surprised any more about a mouse without a ball, although optical mice have been around for only a few years. Meanwhile, optical sensors have evolved to the point where they can easily compete with the accuracy of a mechanical assembly. In fact, they are often even more accurate and react quicker. Nowadays a personal com- puter without a mouse is practically unimaginable. So many operations are carried out with the mouse that using Windows, for exam- ple, with the keyboard only is next to impossible, because you are constantly moving over a graphical desktop. That the (optical) mouse has become an essential part of any modern PC is confirmed by the large numbers sold. The largest m a nu fa ctu rer of opt i c al mouse sensors, Agilent £the former component division of HP), has sold more than 200 million units since the introduction of the hist sen- sor in 19991 In addition there are several other man- ufacturers of these types of sensors and mechanical mice continue to be pro- duced in large quantities. The major advantage of the optical mouse compared to its mechanical counterpart is the virtual immunity to dirt and dust. Cleaning of the ball and rollers is a thing 58 of the past. None the less, there are (or were) disad- vantages. The hr st optical mice were slow to react, inaccurate and power hun- gry. These problems have now all been solved, so only the advantages remain. There Is still one small weakness: an optical mouse does not work well on some surfaces, because it cannot find enough identifying marks. However, tills prob- lem is easily solved with another mouse mat. As a result of falling sensor prices and the simple con- struction of the sensor (prac- tically everything, except the LED, is accommodated in one lC) the mechanical mouse is now slowly disap- pearing from the retail shelves. Camera and DSP Ac first glance, it would seem easy to detect the movement of the mouse using an optical system. But behind this simple idea hides some complex elec- tronics that's comparable to a simple video camera com- bined with an Intelligent digital movement detector. Figure 1 shows a cross-sec- tion of the mouse near the optical sensor. Ah the elec- tronics, including the 'cam- era' part and the lens, are contained in a single IC labelled sensor in the dia- gram (Figure 2 shows a block diagram of the IC). An LED next to the IC provides for sufficient illumination of the surface over which the mouse is moved. The sensor catches some of this reflect- ed light and translates it into an image. The camera section is relatively small, usually only 2Q2G or 30 30 pixels. These generate a black-and-white image for the image -process or (a DSP), which repeatedly performs a pattern analysis and com- pares this with the previous pattern. Using patented technology, the DSP can deduce in an instant in which direction the pattern is mowing and at which speed Figure 3 shows two images separated in time by about 0.7 ms, The processor recognises similar patterns in each of these images and uses these to calculate the displacement in the X- and Y-directlon. Modem sensors have a reso- lution of 400 or SCO CPI (counts per inch) and reach unbelievably high process- ing speeds of around 2500 frames per second. This makes movement speeds of up to 12 inches (approx. 30.5 cm) per second possible! Wireless optical mice use special techniques to reduce the power consumption as much as is possible. For example, the name-rate is reduced when little move- ment has been detected. Finally, a quick look at the output signals produced by the mouse sensor. The cheaper sensors are limited to a serial output, which transmits the X- and Y- dis- placement data to a proces- sor in the mouse for further processing. Larger sensors often have additional quad- rature outputs, which pro- vide signals similar to a mechanical mouse. In princi- ple you could use such a sensor to modify an existing mouse yourself . , Figure 1 . This drawing shows a cross-section of a mouse near the sensor and LEO . (source: Agiient) ■ osc.G-Jt ■ hef & ■ PlErE PO ' CS3 GJiD FESC ’i i.TE-3 YGLTAG£ HSFSTtE?. *C£ 5 VltLT pqwcH :-:czs L 3 Figure 2 . Block diagram of the design of an optical mouse sensor ; in this case an ADN5-2051 . (source: Agilent) Figure 3. These ore two images recorded by the sensor 0.67 ms apart. From this information the DSP calculates the displacement in the X- and Y- direction, (source: Agilent) 4/ 20fl4 - rkkfci eletf ranks 59 Kitchen Table Prof. Dr. Martin Ohsmann This circuit will need just a few micro-amps to make an LED flash. The energy comes from a home made 'vegetarian' battery. We have to admit that the circuit shown in Figure 1 appears a bit over the top for an on/off indicator, as the same functionality could have been achieved from a classic combination of an LED and a series resistor. How- ever, the circuit is unbeaten we feel in that it shows how a visual on/off indi- cation may be realised in battery- powered equipment, while using a minimum of energy, it is of course impossible to make an LED light continuously with very lit- tle current. The solution is to make it flash briefly. Toe requirement, then, is tor a low-energy oscillator capable of creating an extremely low duty factor (on/off ratio). A large time constant is realised by capacitor Cl in conjunc- tion with charging resistor Rl. Micropower op amp IC1 acts as an inverting comparator, monitoring the voltage on Cl and comparing it with a threshold level denned by resistors R2 and R3. Once capacitor Cl con- rains sufficient charge, it has to be discharged, again. The energy stored in the capacitor is of course not wasted but put to good use — in this case powering the LED. In order to create a relatively intense current peah through the LED, the capacitor is discharged through a 1 thyristor tetrode" formed by T1 and T2. This composite device is triggered by the comparator via R5. Because the thyristor tetrode does not consume current as Cl is: being charged and the Micropower op amp itself is an extremely energy-wise component, the total currem consumption remains extremely low — just 15 u A at 12 V. The circuit will function from a supply voltage as low as 3.5 V, although the LED in that case will not light brightly anymore. On a positive note, the cur- rent consumption is then reduced to just 4 jiAI 60 eid.br - 4/2GQ4 COMPONENTS LIST Resistors: Rt,R6 = 1M0 R2 - 3MQ3 R3,R4 = 9MQ1 R 5 - lOOfcO Capacitors: C i C2 = ImF 1 6V (see taxi) Semiconductors; D1 = LED, red low current iC 1 = TS27 1 C (see lexl] T1 - EC557C T2 - BC547C Miscellaneous: K1 = 2 solder pins 2 solder tags 9 copper or coppered discs (e.g. coins, see text) 9 aluminium discs (see text) Absorbing kltchenpaper (see iext) 1 lemon (or pure lemon juice, see Text) 1 rubber ring PC 8, available from The PCB Shop Construction The construction on the printed circuit board shown in Figure 2 is not critical in any respect. Capacitor Cl must be a foil-dielectric type (for example, Siemens MKT). C2. mo, should exhibit a low leakage current because other- wise the current consumption will be far higher than desired. The LED should be a 'high- intensity’ or a Tow- power' type. The introductory photograph shows an initial attempt at construction using Veio board. The circuit employs a micropower operational amplifier type TS271C from ST (formerly SGS-Thonison). This is not a direct replacement form the TLC271, although the !ai:er device may also be used in this circuit if you remember to link pin 7 to 8 in order to preserve the low-bias setting. Resistor K4 which defines the bias current with the TS271 is then omitted. Add some lemon juice The extremely low current consumption at reasonable supply voltages actually allows our little circuit to be powered from a home-made battery. The general idea is depicted in Figure 3. The battery consists of a nine individual elements connected in series by stack- ing. Each element is made up from a (coppered) coin with a diameter of 10- 15 mm, a separating sheer made from kitchen paper soaked in lemon juice, and a piece of aluminium foil. The com- ponents that constitute the 1 veggie batter/’ are also visible in the introduc- tory photograph. Several experiments were carried out and the following procedure was foimd to give best results: fold the aluminium foil eight times and use the circumfer- ence of the coin to cut our eight round packets in one go. Next, cut nine Figure /. Circuit diagram of the energy-wise LED flasher employing the TS271C micropower opamp. square pieces of kitchen paper, the edges should be slightly longer than the diameter of the coin. This is neces- sary to prevent a short circuit between copper and al umini um. Then saturate the paper with lemon juice. Freshly pressed juice will work better than juice from a bottle! Figure 2. A FCB to try it all out. The lower part of the battery assem- bly is formed by a slightly larger piece of aluminium foil — this v/ill act as the negative terminal. On it lies a paper disc. Then stack on a coin, an alu- minium disc, a paper disc and so on. right up to the top coin that acts as the positive terminal If you are satis- fied with your creation, the presence of a voltage may be proved with the aid of a high- impedance digital volt- meter. The battery terminal voltage should be between 3 V and 4 V. Con- nect the battery to the circuit and youTI be able to watch the LED flash for quite a while getting its energy from... lemon juice! ircawcuil e-s-.T-em — copper pnpsr Erad wad ^ -iTiiJVLr" 1 Figure 3. Schematic representation of the battery : 4,, id Q4 - tickler 61 At the heart of this remarkably compact microcontroller board you'll find an ingenious bit of integration technology. The combination acts as a versatile plug-in module for lots of applications requiring some form of intelligent control. Thanks to the extensive software that comes with the board and the presence of a PC interface, our drop-in board is excellent for hardware development, too. 62 elector dtctrffiiits - 4/20Q4 A0DH£SST3ATA/C0tiTHOL EU5 Figure 1. Internal structure of the smart 'all-in-one' chips from the PSD8 13xxx series As many of our readers will be able to confirm, the majority of microcontroller boards look very similar. If the micro- controller used has no program mem- ory, an EPROM is added. Similarly, if there is a lack of RAM, the problem is solved by adding an external RAM device like the 62256. The lot is then complemented with a few logic gates and hey presto we have a basic micro- controller system. In some cases the designer will go one step further by employing a little more than just the microcontroller I/O pins. Some more digital electronics is then in order, but that really wraps it up as far as the cir- cuit is concerned, PS® 8 II 3 series Okay, if all these microcontroller cir- cults are so similar, why not design a single integrated circuit that contains all functionality? Th at way, circuits can become much smaller and the designer could concentrate on those points that are unique to the circuit* This, we figure, must have gone through the heads of several designers at STMicro electronics (formerly SGS Thomson), the general idea having cul- minated in a series of ICs called PSD8I3xxx’. The individual compo- nents inside the chip are found back in Table L Obviously, this IG offers far more possibilities for a wide variety of microcontroller circuits. Figure 1 shows a block diagram illus- trating the internal structure of the PSD813xxx chips. The memories may be mapped on a segment by segment basis. This cre- ates many different configurations, for example, first 16 R Flash, followed by two 8 K EEPROM segments and then another 32 K of Flash memory. The memory management is also very handy. For example, using the page registers allows you to increase the controller's address range. Another possibility is to configure the memory in a different way depending on the page register contents. The samples show how this is done in practice. The CPLD section in principle obviates the logic that's normally required to drive peripheral devices, but only if the designer is satisfied with 27 I/O pins. For a controller with a multiplexed bus, this allows a de- multiplexed address to be created by the chip and, if neces- sary, a tri-state databus. Other appli- cations include generating chip select signals for the peripheral devices or even creating extra I/O ports. The PSD813 series has not been designed for one specific family of microcontrollers. In fact, it is so versa- tile that it can be used with several microcontroller families. These include not only micros with a standard address bus and databus, but also types with a multiplexed data/address bus Like the 8GC32, 805 1XA and the 68HC11. One final point to mention in this short profile is the JTAG port that allows all functions of the chip to be pro- grammed in-circuit. In other words, it is not necessary to buy an expensive programmer — and that's good news. 4/2004 - etekluf eEedroctks 63 ’5V © C3 10»J ■: ypT.a 2 y fi.i 1 yFt z2 X y pi i s V Fl 4 a \F!i 7 y P1.S A y Ft 7 * 1* - : y?= r IS yfSi 7" $ ill 19 A Pi-7 >2 © PH 0TC2 PT.!’Ti=J rl-L^JLB! 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V yf j t yF52 yfCjL yp3-5 yP3 i -3V © Kl c c PI-4 PORT 1 -75V K2 pomp ^5V © \PA = \Fa: O T O ypAz y?£2 y?A4 yLcz_ yFAE_ y FA7 T Kl y AD? yADi y AD2 y AD2 -■ y 4D4 yA4H ' .■ ; jr~ , y*-^- yAiJF 1 y -*5V Afl 3 _jiD 7 FOt K5 O -3 y =5? y rat y FBI y F53 S , P LA y i y PE 7 -: C jn- ■o ■\j PC RT 3 - D T)V © Lc yPCvTUS K5 .■■ yFc-cCft y PC2 yFClTETAT V ^CAT£ "H yf-iC 5 T^ yFC5~3 LJ yPC7-'EK ponrc RESET t:c- GC14* - 11. Figure 2. The application of o P5D& f 3 results in a cons/cferob/y smaller and simpler circuit diagram than you have come fa expect from controller boards . Hardware The starting point for your experi- ments with this chip is a piece of hardware we devel- oped that could be dropped" into sev- eral circuits. The circuit diagram of the drop-in module may be found in Fig- ure 2. Even a cursor/ glance at the drawing should convince you that sim- plicity is trumps. Thanks to the multi- functional character of the PSD813 chip, this hit of hardware may be used in combination with a microcontroller in many different application circuits. What's more, the JTAG interface makes tire total configuration great for use as an experimental or develop^ merit system. For the heart of the circuit we went for a D38GC32G (IC1). This is an 8GC32 compatible micro that’s much faster than the ordinary 8CC32. hence will not lei easily let you down in regard of pro- cessing speed. Its main pins are all connected to the PSD813F in position IC2. Furthermore, the circuit contains a microprocessor supervisor circuit built around IC3 and SI, some compo- nents to complete the clock oscillator and a handful of small caps to clean and buffer the supply voltage. An on-board power supply is not pro- vided because this module will typi- cally act as an add-on to an existing circuit supplying -s-5 V" rather than a stand-alone unit. We did, however, bond out all relevant signals to pins on connectors Kl through K6. Connector K7 is the JTAG interface that allows the chip to be programmed. This inter- face has been described several times already in this magazine. A suitable interface to connect the par- allel port to the JTAG interface is shown in Figure 3. This programmer is directly accessible from the associated program called PSDSoft and that is why we believe ids really indispensa- ble. The programmer is connected to the PC’s parallel port via K8 and a cable with 1-to-l pin correspondence K9 is the JTAG port — this is con- 64 E'zidDr = htrcJfi- 4 5004 'Habile i!. PSD813 fosiefion overview (PSB813F1) Memory management 3 Flash RAM segments (128 k Bytes) 4 EEPROM segments (32kByfes) SRAM [2 kBytes) CPLD (more than 3000 gates] - 27 configurable I/O ports - JTAG port - Programmable power management - Address and data demultiplexer Figure 3. 'Glue fa canned the PCs parallel part fa the JTAG interface.. nected to the plug-in module via a 14- way fiat cable. IC5 affords buffering and inverting of the signals. The enable input is controlled by the PC, ensuring that the relevant signals do not load the circuit connected when in the J off state. Bui idling if Having purchased the printed circuit board and all components you are ready to start building the circuit As shown in Figure 4, the PCB consists of two sections that are easily separated using a hacksaw. One section is for the interface vrith the PC. the other, for the drop-in module proper. In view of the relatively small number of parts, building up the two sub- boards is unlikely to take much of your time. As usual, we recommend you start with the low-profile parts. For the rest, hardly anything that can go wrong If you stick to the compo- nent overlay on the PCB and, of course, the parts list. Connectors Kt -K5 have to be soldered at the underside of the board, their task being to link the module to me host equipment in which is to function. Figure 5 shows our ready- assembled and tested board. Before we can test the circuit, we need to look at the software. Bo f tv/ a re The galaxy of fea- tures offered by the PSD813F1 may star- tle instead of encourage. A chip with so many functions is usually diffi- cult to configure and you may quickly feel lost in bits and bytes* Fortunately STMicio electronics have written a clearly structured program called PSD- soft Express that may be obtained free of charge from their website at www.st.conL The documentation with the PSD813 series is impressive to say the least. The program comes with a wizard guiding you through the configuration process in a step-by-step manner, using unambiguous questions. You'D quickly get the hang of the program simply by using it a few rimes. To enable everyone to make a head start with the PSD313 chip we pro- duced a small example program that may be downloaded free of charge from our website. Toe program demon- strates how extra ChipS elect signals and I/O ports may be generated and created respectively. Having launched PSD Soft Express you are ready to create a new project. Pro- gr ammin g the PSD chip could not be easier using the wizard. The individual pins of the PSD chip connected to the JTAG interface and the controller are immediately assigned names by the wizard* Figure 6 illustrates tire ease of defining an extra OS signal. Once all steps have been completed, the PSD chip is ready for programming through the JTAG interface* J 2004 - slAlm ekcti&rks 65 Components Hsl Resistors; R I = S!L array 8 x 1 Gkn R2 .R3 = StL array 4 x IGkO R4 R5 - 10kQ Capacitors; Cl ,C2 = 33pF C3C4 ,C5 t C7C\ 1 = lOOnF C6 - I OjiF ] 6V radial Semiconductors: EC1 = DS8QC32GQCL (44-pin PLCC) EC2 = PSD 8 1 3F 1 [RS Components #417- 5726) IC3 = MAX701CPA EC4 = 74HCT244P EC5 = 74HCTG4 Miscellaneous: K 1 K6 = 1 O-woy SIL-headsr K7, K9 = ] 4-way boxheader K8 - 25-way sub-D plug {male), angled pins, PC8 mount LI - 1.5 uH miniature choke SI = pushbutton, 1 make contact XI = 1 1 + 0592MHz quartz crystal 44-way PLCC socket 50-way FLCC socket PCS. order code 020148-1 (see Readers Services page) Disk, example project fiEs, order cade 020148-11 or Free Download Figure 4 . The PCS consists of two sections that are easily separated by sowing. Q Design Assistant RtJJie Dsfllbai ^ S-siad Equators j |/0 Logc E^hb j Uss^Aied Hot | Ffif Hdi chp a I b ue«1 §ie ac6f™ six EM fn^p, and ijjiTCnd tsp"-V adiFaL Ensue PSD pay m^ifa iii Ihv? been Sffned 1 tas : 'jTo aui--'.y: i: in zr :r -at . :gi:.-X i\: - rtr ;=tp ir^ -.tlz - i-,rci> "-r*T Vjjc OR usrg r£ '■ i r* ie'c*- U ^ i J f y'-faa fci bjci I D i M sr PSD hdl MC ^ ni :±dde Ti 5 t [pace at ptsw^i PS D EEHiDU tdl inHs n^ii 3 pgHr-^ P^o'ioi Esaca Orif Oats SpasOf^r I rd} fiO hi h2 h3 h4 !j5 El7 5ffii i£s3 cs ;a L r ccr ^-rfHranaroy rt-i—ixur Fags HecStst HcErd Vj-ht AMex i _=ac^ J if : r^L 3 Q jiirt.'i ~ii= -rt=-C ?'3 II dtf* 000 ^ [«* t 1 G?. fJiti n= n=£ft -*rt i =^r~ ^ I L:g.:-b' Ort .-ir red 1 lijfc] l 1 h \ PllJlf KJ^IOT. > /7&c: Mfisji r^r rt^rr^i czrfgj &y\ andE'3 Te£l±si // gT hea bettors. beti so dfeeads &ac^ SB tgfesj :-:j:c = jBsk '-J-IO: L :-m:: : - . Daife cSci arv cr sha ra _ t-: h-HQj £3 atpatj Jh? c^t naete b celxgcar iJS si tfiK wbtfrfr Sifi CUrsCt b fcrNisd c Eotit J _pp=r- _id hf 3l) 5l aiS ill ai2 ill a14 al5 a2 i3 *1 j5 at i? a3 Figure 5. Using ST's PSDsoft Express to assign a so Eva re address range. PmssISy Tlie PSD831 chip offers far more possi- bilities than those used in our simple example. None the less, the drop-in module discussed in this article will not fail to underline the versatility and multifunctional character of the PSD813xxx chips. Together with a suit- able microcontroller, these chips form a solid base for a wide range of appli- cations. The PSD8l3xxx allows much space to be saved in circuits normally requiring an EPROM, Flash memory and a handful of discrete logic. Thanks to the extensive software sup- port and the abiliry to be programmed through a JTAG interface, the chip will easily prove worth its salt during cir- cuit development and debugging. Updates to the chip software and hard- ware (in the CPLD parts) are also easy to implement using the same JTAG interface. Free Downloads - PSD813 example project fife* File number: 020148-1 l.zip - PCS layout in PDF format. File number: 02014S-l.xip www.elektQr-eleclronlc5.co.uk/ dl/dLhtm, select month of publication. 66 44.1l- deriredts - 4/2004 I* I I flewoifc fet PlCmino’ fnkj**Ont roller* Allows users with no programming skills to design complex electronic systems or contact us for a full colour brochure email: safest matrix mu UimEdia.co.uk tel: 0S70 7DD 0831 fax: 0870 700 1832 UJIUI matrix mum media 1 m 7 u J flow-code is a programnti ng system for PlCmkno mi tf&con troll era basket cm flowcharts. Flowcode includes macros to facilitate the control of complex devices like ^segment and LCD displays. Flowcode aliens complete novices to design control systems without getting iw^ed down in tile programming involved. * Requires no programming experience * Full on screen simulation * Pro d u ces PiCmicro h ex code for a range of 8, i8, 28. and 40 pin devices ■ Full suite of demonstration tutorials * Allows complex PiCmicro designs to be produced in minutes for full specification see: www.matrixmuttimedia.co.uk The World's most advanced solution for learning and programming PiCmicro microcontrollers Allows you to program PiCmkros and test you f programs Designed for education, hobbyists and industry Supports low cost Flash programmable PiCmicro devices Fully featured displays including 2 tine LCD and quad 7-segment LED Programs most 8 f 18, 28, 40 pin devices - including those with ADC capabilities Free download software provides seamless send and verify function 3 CD ROM courses in C, assembly code, and flowchart programming are available for frill specifi cation see: www.matrixmultimedia.co.uk ± ■" a Sr S - ■ - + 3 - 1 t 1 * P J *■ ■ ri 1 i A S. A, ■ 91 * « * * ■■ A * m m h t * a a- ± 5 * a m II a- -a 31 a 5. a. " a ih=-I * j m i 3 ' ~'-m L .. L*/ M J I _^r . r If/ If ■ < : Ji or contact us for a full colour brochure mini email: ^abutmuEtiin ecfia.cD.uk matrix lei: 0S70 700 1831 fat os/o 700 1833 multimedia Elec! onic protoyjiig prodr ets and services from the makers of Veroboard ’ Veroboard V\/ero TECHNOLOGIES Vero Technologies Limited Unit 25, Solent Trading Estate, Shamblehurst Lane, Hedge End, Hants, SOSO 2FY 0 CT439 776931 telephone 0 01489 776933 fax 0 sales @verotl „ co m email 3 sales: 087 0225 9505 internet: www.verotl.com Prototyping Boards Extender Boards Wiring and Terminal Pins 0 Standard Backplanes Verowire • Cardframes Front Panels © IBM PC Brackets 4 2004 Elektor Electronics 67 review copy Audio Power Amps ©n the Internet Fewer components, better sound Harry Baggen Audio lovers will no doubt drool over the new Elektor preamp with digital control published in this issue. This, of course, calls for a matching power amplifier! Sine, there are enough high- quality Elektor designs to choose from, but it may also be interesting to trawl the Internet for alternative designs from ali over the world. Eiektor Electronics is renowned when it comes to high-end audio designs. Our magazine frequently nans projects for pre- amplifiers and final amplifiers that are built by thousands of readers. The designs achieve excellent sonic quality at a frac- tion of the price of commercial products. It is in this tradition that we are proud to present, in this Issue, our new digitally con- trolled preamp. The audio sec- tion of this preamp is marked by a minimalist design, guarantee- ing superb sound reproduction while being successfully com- bined with a microcontroller and a display for extensive yet man- ageable control of it all. Such an optimised design calls for a power amplifier with matching performance. Excel- lent candidates from our own stable include the 1GBT Power Amp (June 1995), the Compact Amp (May 1997) and even the Crescendo Millennium Edition (April 2001 J. Audiophiles may however also find interesting designs on the Internet, allowing them to "fol- low their faith 1 . Some people will insist on keeping things as sim- ple as possible, while others will not rest until their equipment is technically perfect. The first category certainly embraces the legendary 'Zen amplifier brought to us by Amer- ican designer Nelson Pass, with follow-up versions carrying names like Son of Zen and 'Bride of Zeal Nelson Is a mas- ter of electronic minim alism — the amplifier stage proper hav- ing just one active element, a power MOSFET. This is comple- mented by no more than a cur- rent source built around a power MOSFET and a transistor. The Zen amp delivers a modest 10 watts in Class A, Over the years a number of variations on the theme have emerged, many or these showing great activity from Nelson Pass himself. Nelson Pass runs a website. Pass DIY [I], containing home- brew designs and covering all Zen projects in great detail AjiQther website describing interesting audio power ampli- fier projects is called ESP, Elliott Sound Products 12}. One of the projects is ominously called Death of Zeri, this is a Zen vari- ant employing bipolar transis- tors. A version actually built from this circuit diagram is found at Eebe [3|. Believe it or not, it is built around the leg- end ary (and still available) power transistor type 2N3055I Another well-known and highly respected designer of, among others, cl ass -A power amplifiers is John Linsley Hood, who in the 1960s became famous through his designs published in Wire- less Y/orld (now Electronics & Vflreless World). A large number of these 'evergreen’ articles may be found at the Class -A Ampli- fier Site 14}. The site also sup- plies circuit diagrams of a head- phone amp liner -and a preampli- fier as well as power amplifier projects from other designers. Electronics enthusiasts who would rather rely on a more extensive design with a sym- metrical layout and higher out- put power may be interested in the v/eh-known power amplifier proposed by W. Marshall Leach, An extensive de scrip non Is sup- plied by the designer himself at The Leach Amp |5|. A well elaborated design for an amplifier with relatively high output power (2 x 350 W into E Q) may be found at a website called A and T Labs [6J The power output section is built around complementary power MOSFETs. Another peculiarity of the design is the application of a switch-mode power supply unit (SMFSU) with a whopping output of I kW. allowing the entire assembly to be housed in a relatively low 19- inch rack. To close off this article we’d like to draw your attention to Schematic. info [7] t a website packed with circuit diagrams of twentieth-century audio classics like Dynaco, SAE, Quad, NAD and Crown. Joke your pick! . iX-ti-T 68 t'd.ui elgdranfn - 4/2004 Internet Addresses [1] Pass DIY: v.vav. pasid: y, cc m /leg a cy. h f m [2j ESP/ Elliott Sound Products: h ftp : / / sound a sihfcsi co m/ind ex . h im j [3] BebeT: h Itp : / / d i yo u d io, 8m .com /Bebel/ b abet . h ton I [4] The Class-A Amplifier Site: wv#w. It aas. bti nlerrvet.ca. uk / [5] The Leach Amp: http: // users .ece.gaJech.edu / -mlea di / 1 ov, ti m / [ 6 ] A and T Labs: www.a-an d-tlab s .eom/K6_Sw_Amp/ }7] Schematic, info: http: / / schematic.narod. ru. ‘ aindsx. hirr hj.T:cl.=.ii i n.-:d CPU (Ci? C-orc-) diMjnuu DSPs at 1 GHz Tap performance from 9i The 90 -nm process technology employed by Texas Instruments gives a spectacular boost to DSP performance. For the first rime, DSPs pass the I -GHz barrier, DSPs (digital signal processors ) type TMS32GC6414/ 15/16 sam- ple at 1 GHz, providing stunning throughput levels. They provide the user with 8 GigaMACs for 8* bit data width for video applies* t ions, or 4 GigaMACs for 16-bit data commonly used in speech and audio processing; Tills sort of throughput not only improves the bandwidth and channel capacity of existing real-time applications like base stations for mobile phones and radios, IP- based video, fast wideband net- works, medical diagnosis equip- ment and radar, but also opens the way to new applications ranging from adaptive antenna arrays and intelligent vehicles right up to artificial vision. A single 1-GHz component, for example, can now manage real- time translating of eight MFEG- 2 channels at Dl resolution (72G>: 480] or the processing of 55 GSM channels using AMT? {adaptive mull irate) speech encoding in a cellphone base station. In this way, designers no longer have to implement complex circuits using multiple processors. The speed breakthrough has been achieved thanks io an innovative design method and improved manufacturing processes employing 90-nm technology, making it possible to produce faster and smaller IGs than ever before. TPs ability to pack transistors in an extremely tight space has resulted in dramatic increases in speed and chip density. The change to 90-mn technology reduces the chip size and with it the production costs, allowing almost 50 Ti: more chips to be made from a single wafer This not only had a positive effect on the new chips, but also allowed the price of the existing 720- MHz 'C64x series to be reduced by more than 50 7 h Toe 90-nm technology also simplifies the integration of System-on-a-Chip architectures by rationalising the communication between the DSP core, memory, peripher- als, RISC processors and ana- logue components. These inno- vations comprise a command pipeline for efficient use at fre- quencies greater than 1 GHz, a dual data architecture with 32 32-bit registers per data path and optimized implementation of data functional units required for the execution of critical pro- gram paths. The new components are soft- ware compatible with the earlier generations — the 'C64 com- mand set was not changed, so the design and process improve- ment are virtually invisible to software developers. The new DSPs being pin compatible with the earlier versions, they can easily be dropped into existing designs, boosting the data throughput, lowering energy consumption and keeping sys- tem costs within reason. The 1-GHz DSPs types C64I6, C6415 and C6416 are currently only available as samples. All three components have an on- chip 1-MB memory and only dif- fer in respect of their integrated peripheral devices. The DSPs will be available in volume quantities by Autumn 2004, Unit prices start at USS 189. To prevent time loss, software engineers can avail themselves of the CS4x Starter Kii and make a head si an with the design of key software elements of a tar- get system, including algo- rithms. command codes and ini- rial software system integration. Tne C64x kit contains didactic exercises, reference framework support, the integrated Cede Compose Studio development platform, the DSP/BIOS real- lime kernel and a number of standard algorithms. The Kit is already available at a cost of USS 395. Further information on this inter- esting starter kit may be found at www ti.cQin/cGODOds ksp. Contact information: European Product Information Center (EPIC) Texas Instruments Germany Haggertysfrasse 1 - 0*85350 Freising - Germany. Teh (+49} 8161 803311 Email: epic@1i.com Internet: www.fi.com/sc/epjc/ www.ti.com/ 1 ghzsampltngp 4/ 2004 ■ eklciof electronic 69 mailbox 64-k 30C552 Flash Board Dear Editor, regarding the above project (January 2004, Ed.) I am at a loss os to which software to obtain for the board and where to find it. Can you help me? Mike Miller (by email) Well ike the article clearly states at several points, including the Free Down toads inset at the end that the seme software is used os with the Precision Measurement Central ( a M5C1210 develop- ment system; cover item, July/August 2003, Ed.). Not to worry., though. Go to va'av. elek tor - e lec iron i cs . co. ukf dl/dihtm , then to issue 324 (September 2003k then select and download the large (!) file 030060- I b.zip. The folder structure of this 'beast is shown in Elektor Electronics September 2G33 on page 54. The S0C552 Flash board also requires file n u mber 030042 ■ M . zip w h ich may be found under issue 328 (January 2004). This zip file con- tains the source code files of the OS552 and Hello programs . cs wel> as r fash 55 2. hex and the GAL source and JEDEC files. As you can see we' ve got if taped f Long(ish) wire Dear Sir, the Longwire Match for SW Receivers article on page 1 1 1 puly/ August 2003, Ed.) has a couple of errors. A long wire antenna is general- ly considered to be long with respect to the wavelength received, that is, at least 10 times the wavelength. The 3- m wire mentioned is actually a short antenna ar HF1 A balun s primary function is to convert a balanced line to an unbalanced one, not to step down an antenna's impedance. The circuit is simply an impedance converter far matching a short antenna to 50 ohms, not a balun equiva- lent for a long wire. Leon Heller, GIHSM (by email] So it is true — length does m of- ten YVb stand corrected yet hops the inappropriate use or the term Jong -wire does not detract too much from the usefulness or the circuit . CoolRunner-Il — not so cool Dear Jan, I was sur- prised and somewhat disap- pointed to see that the Xilinx CoolRunner-!l Development Kit reviewed in your February 2004 issue could not actually be ordered from the Xilinx website using the hyperlink you printed. The product seems to have been discon- tinued. As I am still interested in making a head start with CPLDs, Td like to know what, if any, replacement product you or Xilinx recommend? Stuart Galbraith (by email) Things are moving last in the sili- con chip industry — faster than we can print pages and get them into the newsstands or your mail- box. literally minutes oner hitting the Return key and sending our magazine to the printers we too discovered that t he product had been removed from the Xilinx website. Fortunately, within coys Xilinx advised us that the CPLD Design Kit ( part # DQ-CPLD-DK) is o perfect substitute. YVs were g ad fo see that the new kit con- tains even more goodies than the Coofrunner-ll while me price has remained the same at S 49W9 plus shipping. Where to start? I am cur- rently travelling the world and have just bought your magazine in OZ (is that Denmark? Ed.}, I come from the UK but have never seen your magazine there. I wonder if you could help me. 1 would very much like to learn about electronics but after years of trying to find evening courses, 1 gave up. Do you hove any suggestions □s to how a complete idiot to electronics can learn about electronics. I am not very good at learning from books unless it has a large practi- cal content. Tim (by email) Hello Tim. and •welcome to Elek - tor Electronics. We envy you, being confined fo our offices and answering readers' letters . Amaz- ing you have never seen our magazine in the UK as it has been around in vast quantities since 1 975. May I suggest you follow our Mint Project article series ? The complete series is available free of charge from our website, simply click on Mini Pro- jects Online. We re sure you'll find the content far from bookish. Mirror mirror on the wall Dear Editor, l have a problem with the RGB layouts in PDF format. I need to print a mir- ror image because I use the 'print-iTon-a-laser-printer-and- iron-it-an-the-copper method of making PCBs. The Minolta Pro 6 driver for Win 2000 has no provision for printing an mirror image, and Acrobat Reader does not seem la do it by itself. Moving the design from Acrobat Reader to PointShop Pro or some other graphics program seems to destroy the fine lines by pixel- lation, if you know what ! mean. Can you help? Per Troeisen, probably the most faithful subscriber in Denmark [ 15 + years) (by email) Per , ; despite being a faithful reader yo u m ay have miss ed fh at since mid 200 f our PCS down- loads contain pdf files with non- reflected as well os refected art- work. See also J Printing PCS Art- work' in the May 200‘3 issue. Alarm! Clock deviation! Gentlemen, the liming error admitted in the Digital Alarm Clock article [February 2004, Ed_] — 0.256 ms slow per minule — amounts fo just over a third of a sec- ond per day, or two and a quarter m Enures per year. However, looked at another way, it is equivalent to the 4 MHz master oscillator run- ning 17.06/ Hz stow. In practice, this is far less than the likely frequency error for an unadjusted oscillator of this type — possibly by an order of magnitude! Might I suggest replacing one of the fixed capacitors C 1 or C2 with a small preset trimmer? Then adjusting the oscillator to 4,000,01 7.067 Hz will allow the clock to keep per- fect' time. Mathematically, at least, it is also easy to correct the divi- sion ratio so that on accu- rate 4,000,000,00 MHz dock (adjusted as above) will keep time, but whether this is actually possible with the PIC only you can answer. Apparently you use the overflow of T1MER 0 to increment a 16 bir counter. If this 8-bit T!MER_0 counter could be preset so that if divided by 160 instead of 256, and the 1 6-bit counter set for □ maximum count of 46875, this would give o precise 60 second interval. If TIMER_0 can only divide by 256, could the prescaler be set to divide by 5 instead of 8? That would achieve an identical result. 70 TAinj siTEtrcEirts - 4 200-4 If would be ideal if the divi- sion ratios could be config- ured accurately os described, then the 4 MHz oscillator could be more easily adjust- ed; a frequency reference %vou!d be available for other uses, and fhere would be the possibility of using on exter- na] ] MHz dock. However, failing Shot, simple adjustment as described in the first para- graph would at least give accurate time-keeping, Peter Vince (by email) Te designer o': the circuit , Manoel Conde be Almeida , replies: You are right. The 0 . 256 ms error is the admitted error considering mat the crystal oscillator will run at the nominal crystal oscillation frequency (in this case 4 MHz). Of course, we all know that off the shelf crystals have c tolerance o f around 100 ppm. The idea of replacing one of the capacitors by a trimmer looks good and seems to be the most effective one. But we have to rememther that if would require special equipment (a calibrated frequency meter, for instance) for the adiusfment process. Some readers interested in building the dock may not have that kind of intros iruciure available. Using the firmware (mathematics) is on alternative but, since we never know the exact frequency the oscillator will be running at (assuming that the user does not have equipment to measure/ adjust the frequency j, it becomes more difficult to develop a 1 00% accurate solution. Anyway along that line of thought I have worked on a firmware solution that fries to min- imize the issue by giving the user 4 he opportunity to change the maximum count of the register that keeps track of the T1MER_0 interrupts and updates the clock $ seconds counter. The user may select l ot 3 oper- ating modes depending on the clacks behaviour (slow OK, fast). Each mode establishes different maximum counts for the TIMER O counter it dcesn i salve the problem en ti refy ■ be/ m in im ize s the erro r when the oscillator is running near the limits of the crystal tol- erance . The solution, though., works with the PIC1 6F62B and not the PIC } 6F34A because of programming memory space, if you re interested I con share mare information and exchange more ideas v/tib you and other Elekfor readers. Self-discharging NiMH batteries Dear Jan, in a recent article on digital cam- eras published by a renowned computer maga- zine 1 stumbled on the follow- ing rather bold statement: NiMH batteries suffer from energy lass at a rate of about 1% per day", I am not an electronics buff and although the statement does not came from any of your articles I would still invite your com- ment? G. Lisabeth (by email) The statement is correct All ceils lose energy owing to seif ‘dis- charging and NfMH batteries are no exception . Although the exact rote of discharge depends on the cell type (i.e.. Technology ) ' 7 "n per day' is a generally accepted value, ECD CD-ROM Dear Editor, I recently bought □ copy of your ECD CD-ROM. I have a few questions on the product: 1 . Reference is made to an elusive 'booklet explaining the installation and use of the CD-ROM. What 1 was able to find was o leaflet (inlay) giving just the minimum sys- tem requirements. 2. Is it possible to use the CD-ROM without having to copy the lot to hard disk? If so, how is it done? I was unable to find any guidance. 3* Eventually 1 did install the product an hard disk and found it a pleasure to work with. My only objection is that a subject hos lo be closed before another can be selected, or am 1 missing something? Otherwise, full marks for the ECD! Robert Fruytler (Netherlands) Thanks for your pos Hive c ri itch ms Roberf ! and glad to read that you like the product. As the installa- tion is mostly self-evident, any sort of description is super Hue us and would not hill a bookie! any- way. There's no way you con avoid copying all data on the CD-ROM because the immense size of the component database makes it impossible to handle mom CD-ROM particularly on slower PCs . These s no need to dose subjects every lime. Several subjects may be opened in sequence and you may switch between them using the ALT-rTAB key combination (yes the method dotes bock to Win- dows 3.1). The selection menu is also areas Able by right-clicking on the icon in Ike status bar. Economic forces Dear Publisher, thanks for your notice to renew my subscrip- tion to Elekfor Electronics this year. Your information that you have to increase the sub- scription rote yet again this year due to economic rea- sons, l fully understand. Unfortunately, due to the strong British Pound and your increases of subscription over the last three years, the cost of your magazine is no longer affordable for myself. This is very disturbing for myself, but having been a reader and subscriber of this magazine for over 26 years, l have, with o heavy heart, decided not fo continue my subscription to your wonder- ful magazine. The main rea- son is that, being a pen- sioned person and still active in various fields of electron- ics, I just cannot afford it any- more! I wish you all the best and hope you will continue to produce a wonderful and A-l magazine! Sejjad Satam (Slovenia] Sejjad, we were sorry to read your email bur fully appreciate your problems and thank you for having been a subscriber tor so long. Despite the recent price increases we can still claim to oner the best cost per circuit fig- ure of all electronics magazines published m the UK. V/e hope that in the future you will still be able /a pick up the odd copy of Elekfor from o news- stand if a subject to your liking is published (do check our website — - it is free). Mail Box Terms - Pur. car c - o i r ead srs core s p un- kBP.ce is at the rtsers-ion ot ihe Eater - 'new cams expressed by cow-s- pon d enis a? e n ot nec -ss se: . 'braa ot the Editor o - Plo 3 she-. - C ojTssp-sn d cream a . b e u an s latsd c r ad tied for Isr.zVr. ■: a ? I : , srz style. - When rep ! yin a to Wait box cofre £ pandance, pi ess e quota issue number. - Base cL r Be ■: corre- spondence to: an 1 s.r5.ff etektor-e Esc Ironies. cg.ux - - Elekter E; sc homes, The Editor po. Sox 193 t Tunbridge We- Is TN5 7V A' England 4/2004 ■ elcldcj efecfrcr'cs 71 news & new products SMART Ships One-Millionth Bluetooth Module SWART Modular Technologies, Inc., recently shipped its one-mil- lionth Bluetooth module since January 2003, an important milestone that demonstrates the relative success of the Bluetooth technology in the short-range wireless module market. SMARTS Bluetooth modules hove been designed into PC, PDA, medico!, consumer and industrial products. SMARTS communication prod- ucts division (CPD) has devel- oped a brood line of Bluetooth- enabled modules and devices to support GEM/ODM designs ot all stages oF the development cycle. SMARTS current product and service portfolio includes USB and RS-232 Bluetooth adapters, mini-modules and developer boards, as well as complete product lifecycle sup- port built with next generation technology. According to a recent report from In-Stot MDR titled, Bluetooth 2003: Are PMGs Another Dri- ver, over three million notebooks with Bluetooth ore forecasted to ship in 2003, which indicates a significant increase from the pre- vious year. SMART Modular Technologies, Inc* PO Box 1 757, Fremont, CA 94538. TeL {+!) 51 0*623*1 231, fox (+1) 510-623-1434. 1 nt erne!: vrv/w.s tna r t m odu! artech . co m - - FRUSTRATED ! Looking for ICs TRANSISTORS? A phone call io us could gel a result. We offer an extensive range and with a world- *ur- wide database at our fingertips, we are able to source even more. We specialise in devices with the following prefix no name but a few). 2N 25 A USB 2 SC 2SD 2P 2SJ 25K 3\ T 3SK 4N 6N 17 40 AD ADC AN AM AY BA BC BD BDT BDV BDW BDX BF BFR BFS BFT BFX BFY BLY BI X BS BR BRX BRY BS BSS B5Y B5\Y BSX BT BTABTB BRW BU BUK BUT BUY BUW BUX BIT BUZ CA CD CX CXA DAC DG DM D5 DTA DTC GL GM RA HCF HD HEF ICL ICM 1RF J KA Kf A L LA LB LC LD LF LM M M5M MA MAB MAX MB MC MDAJ MJE MJF MM MN MP5 MPSA MPSH MPSU MRF NIM NE OM OP PA PAL PIC PN RC S SAA SAB SAD SAI 5 AS SDA SG 51 5L $N 50 STA STK STR STRD STRM SIRS SVi TTATAA TAGTBA TCTCA IDA TDB TEA TIC TIP TIPL TEA TLTTXTMP TMS TPU U UA UAA IX LDN L'LN UM UPA UPC UPD \XXXRZ ZX TVS + mam others We can also offer equivalents tat customers' risk I We also stock a full range of other electronic components Mail, phone, Fax Credit Card orders and callers welcome r SttfTPC** Cricklewood Electronics Ltd 40-42 Cricklewood Broadway London NW2 3ET Tel: 020 8452 0161 Fax: 020 8208 1441 The new Elektor Item Tracer (EIT) is now available! EIT contains the digital con- tents list of all articles (except news columns) pub' fished in the magazine over the period 1985-2003, EIT 1985-2003 Isa user-friend- ly program supplied on a 3.5-inch diskette, running under Windows an d offer- ing art attractive graphics interface. The program allows searching lor various keywords or combinations, such as name of ankle: name of component: classification (audio, computers, ere); special components: order number of PC 6 or soft- ware item, EFT prints hard copy via the Windows printer driver. Order now using the Order Form in the Readers Services section, or wrete 10 P.0. Em 190 * Ytefc TH5 7WY ■ Ezjkri T ^44 {2) 1 5SG 2W fi57 • Fu ^14 (ft 15e3 m m Internet www.elektor- eIedranks.co.uk tm rumc.vci * cc«^th hj 72 deklor electronics ■ -5/20G4 Visit our website 1 v/ww, disteLco.uk | 1 THE ORiGINAL SURPLUS WONDERLAND THIS MONTH'S SELECTION FROM OUR VAST EVER CHANGING STOCKS j \ Surplus always 1 wanted for cash! | GIANT 10" 7 SEGMENT DISPLA YS I 1C 's -TRANSISTORS - DIODES A bu & pjciiass ecais'ss us s b ina to you teese GANT 7 sagrrert dote dspS'jS e- s now affordable pets’ The 10* character $£m g-saz Exregtara reed* abiry st eng dstertes aid cnadbs a Ixei tf sepks- terre hdUSng score boE-tes. elghal docks, cbm* tere, evert timers ete, A* tha urvts are a simple eteCTxnocharical de»«fes and eper^s tern 12 V DC. srepb re,vtoVng va ?-vxhes tessys. FK cr PC may be used to Conner angfs or misiteegs Unis feEtia rfstjra ’Zero* FtWfEf’ msmciy Vitteh gnaaSy sjn-ptfes d&sgn For an excellent CHY practical Kittdt, see the t.tey ssue of EVsydsy & ProctkaJ Ekctronics’ magazine. kJeal School / Co&E-ge . sSructfin project Sc^pfed ri coto RFE tm&ri pcnn^re- j— z rere errjcA Less than 30% Only £29.9 5 ss) or 4 / £99. 00 [dj of makers pnee ! cnteFW44 CntrR-06 THE AMAZING TELEBOX TV SOUND & VIDEO TUNER CABLE COMPATIBLE ’ Converts your colour manlier into a QUALITY COLOUR TVH The TELEBOX is an atiractre ?Jty r aasr l m£53”£i pCV^Tcd UTIL L-M JcSiirQ LI etouLu ite raa dy to pfeg into a hc&cf vijao rnernors cr AV egUprnert VirikJi are Eted win a ccrrpcStevtoao cr^ART m.: __ o zenpeste ltoec O-re-re *4 Ao plug csbcc/ too most recordere, afcwiv] reception c‘ TV crwvxjis not nermafy receivabte on most foe. foie n. receivers* (7EL:=- BGX Pjst bu^jn ccrcxfo on tie rnrt pern sSom rBcapccri a £ : . . zre=&3 r or bj L rr cdtxr i&fe.iErn crsirek. TELEBOX MB totors ,to- =>j bJ Sequences VHP and Ukr todutfiig the HYPERRANO as usd byrrwst cebte TV operated. kssf tor desktop computer video sys- tems & PF (pcLrs h peters) Fir gnpi^ COFfUi% - even for rr criters wml sand - an aiJOSTpreraid bw fev^l J-i Fi BJ30 ojikj. aa prtvidsd as sanJ^tL Braid raw - rJty gtarartgal TELE BOX ST f br rarrpcslts video toput ty^e montora £36.S S TELE BO X STL es S i but frtisd w Si totsg ra: s peaker £29. £9 TELE BOX MB V uftfcaml VHFAJHF/CabJtTTypsmanci tuner ££9.95 For cvgrssaa PAL versons state 5.5 cr 5 mHz sound spe cifcafi on. r r csb 5 ' byperband dgnal recepLon T&letot MB shoukl ba oo rt- 'c a cab's r/ps seYsa. Shipping on c£ 4 Teebox's, code {BJ State cf the art PAL (UK speci UHF TV tuner module com posits IV cp Vbsc 4 NICA.M hi Es s-sreo sound outputs. Micro electronics a i cn or^ srrs.3 PCSonty 73 x ' 1EO x 52 mm enable M tuning con trot va a simpte 3 wire link an IBM pc typo computer. Suppled corrc'ala wjtii simple working program and dooimer^tadoa Rflqu'fas -T2V & + 5V CO ts operate, a RAND NEW - O/tfsr as AfYOO. Only £3 9 . 95 corfe fB; Se-s v. cGr f 9 co. uk '<33i3_nyyQQ. h Sm for picture + fufl details HARD DISK DRIVES 2%" - 14 OBSOLETE ■ SHORT SUPPLY ■ BULK 10,000,000 items EX STOCK Fcr MAJOR SAvmas CALL or see web site www.distelxo.uk COMPUTER MONITOR SPECIALS Legacy products High spec genuine multysync. CGAj EGA, VGA, SVGA FA3415ETKL U' SVGA HiJ^ync cc±^r nxx*r vt&i 030 dot pkh kite erei i^ci^cn cf 1024 x IBS. A van 1 - dy of alcws g~ mpt-rn -i to a hcet cf ccrnpJ^ri irscftjcL-g IBM PC^ n CGA, EGA, VGA & SVGA modes BSC, COMMODORE ircuaha Amga r?:^, ARCH EM ED ES end APPLE. ’,fen\ feetxes Etched tecef^ teal and LOWRjUMATIOH MFR spaffCEtton. FnLuty guar^fesd, r; EX CELLE- TT itfe CjBed cnt±±XL Td & S .'i^vet Esse £4.75 VGA csbfci fef ISM PC Ir^ldod Only £129© ExfemaJ cahtes fDT other types cJcompuj^s - CALL Generic LOW COST SVGA Monitors We choose the make, -which includes Compaq. Mi!subushi f IBtA r etc Supplied ready to mn with ail cables. Standard RTB QG day guarantee. 14’ 15" 17 n £59.00 £69.00 £79.00 c refer TD84 order TG2 1 ornerTJco Supplied in good used condition. Shipping cods fD; *Pi 2"t 4 l’ T/i 1 : 2 f AT y-.‘ yy £'. *’ 57/ 5"V SVP 5%* TOSHIBA MK1002MAV 1.1Gb laptop!' 2.5 trP Hi New £59.95 3 2 mm H ■ h’Fiv £ 1 □ 5. GO 12.7 rrsr. n New £93.00 '12 mn H H=a£ 149.95 see TOSHIBA MK43 i 3MAT 4 3Ge faoicp TOSHIBA k!K£4^VAV c.lGa TOSHIBA MK1S14GAV 16 Gp laptop b 3%" popvaraicn ka far Pc's, comotete ¥itth conroecttxs El 5.9 5 COMPAQ 31 37»‘321 (I3M) 9 gb ULT/SCSlS Wew £1 99.00 F U J I F K-3d9'26 2C?r b MrM l/F FIFE £59.9 5 CONNER CP3024 20 mb IDE l/F (o- equiv.J R-E £59,95 CONNER CP3044 40 mb IDE I tr (t^requiv.) RFE £69.00 Q U AN TU M 40S P rodrive 42mb SCSI L F. Hfff- RFE £49.00 VIM SCRIBE 3425 20mb MFU Ur (er eq-iv.) FEE £49.95 S EAG ATE ST-Z3SR 30 mb RLL L r Reft, rb £69 .9 5 CO C E42D>51 4Dmb h H FLt LF RFE tea ted £69.9 5 HP 97545 650 Mb SCSI RFE tested £99.00 HP 03010 7 Gbyte SCSI tTirferentisf RFE tested £195.00 NEC D2246 S5 Mb S»,'D Intoface New £99.00 FU J rTS U ? . J 2322K 'SO !,fb S !■' D IF RF E tested £ 1 9 5 .00 FUJITSU M23&2K 2 Gb SVD l/F RFE iestez £345.00 other floppy 6 H dm es r tDE. SCSI. ESDI Etc tram stock, ivebsfte for full stock list Snipping on all drives is cod 9 (C) V: -atted & bocted. Supp'ed BRAND NBV fid gsjsj-. as QG3S “te-id. Fcr ful dsta see fealued item can website. Qnte °"iy £99 - 00 « TEST EQUIPMENT & SPECIAL INTEREST ITEMS ttu& section are pre owned. MrrSUBUSHi FAS445=TKL 14 T Ind,Spei SvGA.r7c--.--5 £245 PARNELL 0-60V DC @50 Amps, bench Powa Suppfees £99s FARN ELL AP30 5 3 G-30V DC @ SO Amps, bench Suppy £1 850 K1 WG SHI LL C2403J 1 0-5GV g OC 200 Amps - Ne/. r £ 39 50 Ik'iVts-rOOJ^/ - 400 Hi3 pJtasa power iOLrcBS-exEtDck £POA IBM 8230 ypa 1, Token rTtg idsd urflt £760 Wayne Kerr RA230 Aix'0 fr^auency ffcSXX-Lsa &Ra':y ser £2500 INFO DEC UJ, 24 port, RJ4S network pstcn^els. =T.v^3 £49 3COM 16670 12 Port Bhamet hub - RJ4S cortn&rtr ■ =_: I “ £59 3COM 16671 24 Port Ethernet hub - RJ45 connectors £39 3COM 16700 & Pod Ethernet hub - RJ45 connecters NEW £39 I B M 53F 5s01 Tqkcn R'ng ICS 20 port ?-obe modlies £P DA IBM MAU Token ring rjBqikjfcn pans! 8223-23-5C-/N £45 AIM 501 Lew detortjon Osc later 9Hz t-a 33CK hz. IEEE O £550 ALLGON 5 360.1 1605-1 &&Q MHz hybrid pcMx: comfeners £2 SO Tren d DSA 274 Date A r a tyser w th G703 : 21 / ) c4 Uo £P DA !,\ -1 rconi 6310 Prog ra Tjr.sbte 2 to 22 G Hz sweep gaiere m - £ 4 50 0 Marconi 2 022C 1 0 KHz-' GHz RF s tens : generator £ 1 550 HP1658B Logc Aroa^r £3750 HP3781 A Pattern generator 5 HP3782A Ern^ Detected £POA H PE 62 1 A Dual Prog mimiafc fe GPIB PS l) G-7 ' J 1 60 £1 80 0 HP 62 64 Rack mount variabie 0-2GV @ 2CA mstertz F3U £475 H P54 1 2 1 A DC tei 22 GHz four chan ns I t&Sf fiet £P DA HP31 30A opt 020 2. _ T 1 !-^ p jIkj- gener3ter x GPIB a;- £7900 HP A1, AD B pen HPGL f^h spesTdrum plcteirg - from £55Q HP DRAFT MASTER 1 B pen hSqh Epesd s'etter £750 EGtG Break deal 9SQ3SC Pi'a&si^n lock 'r. amp £1600 Keith ley 5 90 CV capacitor / vptte”a a ns'i’se r £ P 0 A Racal ICR40 duai40 diannel w& reesnder system £37=0 Flake ra 45 KVA 3 ph On Line LFS - N Datsedes £4 500 Emerson AP1.30 2.5KVA ircustnal spec UPS £1499 Mann Tally MT645 H fllt speed Ena printer £220 0 Intel S E C 40 6/1 33 3 E Til L. T bits 466 sy □ term. £ Mis Rsrn £ 9 4 5 rf4° W' f 9” RACK CABINETS Europe's Largest Stocks of quality rack cabinets, enclosures and accessories. Over 10Q0 Racks from stock This month's special 33 / 42 / 47 U- High Quality All steel Rack Cabinets M=:te t } Eufocrafi EncinsnrE-s Ltd tp the higlrttl pos- sible spec* ?=$: featems all steal construction with removabte sade. front and heck doors- Front and b=to. daers ere hinged for e=sy access and a! 'cAsbte vvtii frre secure S lever barrel locks. Tne front deer is constructed cf ccufcls wailed 5iB£( vrA e 'designer *tyts p smokod scry 1c Irofii □a jig; Ld anehls statua indicatcrs £0 fc = seen inrougn Lhs panel. yGl rGjnaJn unobtrusive. Internally the rack faater&s fui3y slotted re.n- fz-rc©d vertical mend rnembeis to take the heavi- est of 19^ rack equipment- The two movaca ■,i erircal fbd^g struts (extras avs afcia) are pre pjnEhed for stoidted cage mis a malm dis- tribution panel Interns ;y meurcted to tha batter rear, prorates 6 x IEC 3 pn Euto sockets sr.-d 1 x 1 3 amp 3 p^'n switched utility sockeL 0-,-era ' vsntte- tion is pxr.iced by fu£Iy tauraed tack cocr ard doubfis ste'np-d tep sacton win tc-p and side teuvrBS. Tea top parte may t-a rs r-^r^c for Friijna of integral Fans to the sub plate etc. Other features r.o'ude: rtied csstete a.hd floor te-re'ers. prepunched utahy pane! at -wte' tesr for ESP*e f cmnecfcf snoess. ete S '.tested : n cxceFTent s :ghby used conoteon «uh keys. Cc'aur Roye* qd=. scrr= gr=y avg2=t]. r e - CALL - Csn te suppLea >n msny other ocn^guratans 4 y VIDEO MONITORS PHILIPS HDS35 ^same sz,.e as Ci,fSfl33) e^zezz.e ,■ stated 14 T colour miMitetr wifi both RGB and standard composite 15.625 Khz video inputs vte SCART soefart a.nd sepsrete phoru fads. [niegrgl aud o_pow0r amp and speaker for all audio visual uses. WE connect ccrast to Amega and Atari BSC ccmputers. deal forafl video monitoring I security aoc.^icns w\d\ direct connection to most colour cam eras, rlgh cuainy wih many festures =-.rh as front concsalad FkSp cocitr&is^ VCR correction button etz. Good used ccr-ditoi - Fuf-y tested - c uaraidaed nn(ir TQQ flH E 3 inenskns: W14" x H12%Tit 15> 4 " D. UMiy wd,UU PHILIPS HCS31 Ultra compact &* cc!out vkjeo reofifliir vifth stan- dard composite 15.625 Khx video input via SCART sockete kfeal far sE morfejraig / sboi% appScsSons. High quarry, ex-equipment fufly tested & guaranteed (poss^te nwior screen teens). \n attract CVe square b-tec-. tesscc csss measuririg V. r t0’ x Hl0 v x i 3Vl T D 240 V AC mtens powered Qnly £ 79.00 (D) INDUSTRIAL COMPUTERS TiJty shoebox sized industrial 40 JXnz 3S6 PC system measuring onfy (mm) 266 w X 63 h X l 2; fo* LfaisJ contrei appE- cadons running DOS. Unux crevsn ddrzkr wa 1 Etete case cc-n- Lains 65 to 265 V AC 50 / 60 hz 70 Watt PEL), s 3 slot ISA passive tad^c ans and a Rocky 318 (PC 104) standard, slso'e beard com- puler with 9 MByte NON VOLATILE soid state 'Disk On Croa’ RAMDISK. System co mc ri sea; RcoSry 3 IB (PCI 04) S3C ISA card with 4CM-{£ Aii 336SX CPU, 72 pin SIMM skrtwhh 16 Miyte Si MV. A'ld BIOS, battery feacksd up real trite dock. 2 x 9 pri D 16S50 sariaJ porta. EFP. tCP printer pert, jnrij. DIN kayboard ccn- nactc-r. *?zzzy pert, IDE pen for rafo drives 143 te 523 MByte cap£diy» watchdog triw and PC/ 104 bus socket. The 8 MByte G- .a stats csk cn a cn p' has tte o-.^a BIOS, snd can b ■=- fo skc-3 33U 42 U 47U Order as SC44 Order as DT20 Order as RV36 External dimenstorts External □ menerens External ditnensfons rrre— 1E25H x B3ED s msn=20l9H x £350 x n"Ti=2235H > S1SD x 603 VV 64' H x 25' 603 W (79.5’ H x 25' 603 ,V. m m H x 25' Dx23totoY i D x Z3Y* W J D x 23-' L \\ Only Only Only £245 £345 £410 Call for shipping quotation COLOUR CCD CAMERAS I r 5 /a «# HP 60 3&A 0-200V DC L 1 7 Amps ter.Ch kja er su pziy £ 1 9 50 Intel SBC 460/1 25C0B Enhanced 1 ttee (?/ S A Now El 1 50 Nikon HFX-11 (Ecrifo-tteti exposuru ccrrtrci \pid £1450 PMIUPS PM6510 C.-0. TV signal generate: £1250 Motorola VME Sls Scsrds & Ctompcnents Lis- SAE CALL £POA THo 0-1 B vdc inear, meteFed 38 sire bench P5U New £556 FuSKsu H304 1 R 600 LP !A htoh scesd t3nd printei £1950 Fujlts u M304 1 D ECO LP.M pHrte - wrri neteo^ fniefece £1 2 50 S lem sits K446D 64Kb to 1 4D?^b demtef anaJyser £29 50 Perkin Elmer 299 B Infrared tpadw^ofefli tfiir £500 Perkin Elmer 597 Iri^tared scectnx^temete: £3500 VG Eisclren'ca 1035 TELETEXT Decodtog Ltere.- Veter £3250 Lig h tBend 60 output h 'gh spec 2u rad t mount video VDA’s £495 SskonlcSD 1 50 H IS criaAJte! d -g 'tei Hyx cr-.zri rEz^zzz- El 9 9 5 BSK 2633 STcrcphofte pre amp £390 Tsylor Hubson Ta^’Suif amplfer / nsenfsr £750 ADC SS200 Carijon dritodu gas detoefo' 1 monitor El 450 B BC AM20/3 FFV jErr-Gsl Tlctc’ 1 ) + driyfi eteebunk^ £75 ANRlTSLr 9E54A Optical DC-UGrb wavofarm monster £5650 AH RITSU VL93A optical pc?^r ir +2 ter £990 AH R fTSD R bra optic characterise test set £F O A RSS FTD2 D"ub? souid un4 £650 RS S SB UF-E 1 Vlsfon modiM £77 5 WILTRQN 663CB 12A /2GGKzRF sateen generator £5750 TE K 2445 150 MHz 4 trace osci to s cope ' £1250 TEK 2455 300 Mhz 300 MHz car- ItecDpe ratk mount £1955 T E K TBS3&Q 4 CC Mhz dig tei ma itt e - c 3 k d rore. FFT etc £2 3 90 TEK TDS524 A SOOkfitz vgital reaMme + cpicu: display e!r £5180 HP3565A Oct 907 20Hz te 40 ?.(hz $p$ctrum analyse* £3950 P Hi UPS P^ W 17 39 1 0 60 KV XRAY geno rater a accssssr-t^ £F O A VARIACS - Large rgnge from elock - cali or see our wabsite CLAD DE LYONS 1 2A 24QV & n gk* pria&e ante- rugs £32 5 C LAD D E LYO N S 1 (XlA 240,4 1 #7 3 phs =3 3 Jte - v;,L rags £2 980 Un zesec COLOUR. CCD cs 'ters 3t a g, .e away fiz-ze ! Un-1 features ful autoCc't sens. ‘3 for use in low light 4 high light ^ applications. A 10 mm reed focus ■Aide a"g!e tens gives BicelJEnt focus and rea-clution mom ttese up to tong range. The composite video uutpul vri :^MV>ec; to E_r.y ccmposSe men “tor or T, (via SCAR 1 socket) and most video reccrcera. Unit runs from 12V DC se ideal for seourity & portable applies- tfotis where mares power net avaras’e. Grera djmenstons £5 mm wide x 117 cbm x 43 high Suppfed BRAND NEW 4 fu'ly guaimtffid wbh user dsa, ICGs cl szu cs- Itors inefudrig Secrefoy Htrera \fofere Web VS Vfob Cams sfo sfo Order as LK33 ONLY £79.00 or 2 for £149.00 a SOFTWARE SPECIALS NT4 Workstation, complete with service peck 3 and licence - OEM packaged. ONLY £89.00 e ENCARTA 95 - CD ROM, Hot trie latest - but at this price ! £7.95 DOS 5.0 on 3’A‘ c£sks with ccr/nss bocks cau QSssfo £14.95 Y-^fidows for Workgroups 3.11+ Dos 6.22 on 3.5 11 disks £55.00 Windows 95 CDROli Orely - Ho Licence - £19,95 WordPerfect 6 for CCS supp ed cr jL' _.s- i .■» te £24,55 shipping charges for software is code B SOLID STATE LASERS VM&te red, 670nrn Laser dote Urel rm& ftwn 5 V DC st acprm £D rrA Originally rriECB for continuous use n irKfustr.dJ ba.'- caaescantets, the Laser b moonted to a removaUa sofid atomtoktr btodt, which fujicdcns as a hsaterik ard rg'd oprioai mottoi Dirrs o f : zck ere 50 wx SOd x 15h mm. Irrt^raJ features hdjde cve- 1 rerrv r-erature current corriml, laser OK ouput, and gated TTL ON t OFF, Many uses far expehsTtgrtal optics, cc rers i . - tiihp#s ex Supp'.«j corr-ptete .’. ten latesh&st Ortfer as TD9* QNL Y £24. 95 {a > f DC POWER SUPPLIES Virtually every type of power supply you can imagine. Over 10 S 0Q0 Power Supplies Ex Stock - Call or see our v/eb site. RELAYS - 200,000 FROM STOCK Ssye ££££*£ by choosing yv- r next rz ’ay to r-^ r M assise Stccks contwig types such s-s MMary, Ocf^ CT^cPe, Harmstk^My Sesferf, Car7fjhfli7fa/ t Contactors. Trme Delay, Rsred. htercury t'Adsri, ScfeJ State, Printed drewt Mourdr-g etc. . CALL or see our web site pyww.djsfeJ.co.uJr fcr mere information, Meny obsolete types from *:ock. Ssi-s £E££fo * ■ * * *»* till * t t I 1 ft I i * ft m « n« * * * * * 1 1 1 ■ » • ft « i # • ft A mm m ■ * ■ * ft • • ft * ■ ■ m * ft*! « a m « v V A • A 1 -ELECTRONICS- ALL MAIL TO Dept 29 / 35 Osborne Rd Thornton Heath Surrey CR7 8PD. UK Open P^on - Fri 9.00 - 5:30 IB Million items On Line Now 1 Secure Ordering, Pictures, information vfnsign www.distel.co.uk email = a dm in&dlstel. co.uk be cure ALL ^ ENQUIRIES 0208 653 3333 FAX 0208 653 8888 r I 1 1 mm v. e 26 to :„v v.i ■ •„< qjy.y-ers ax' T 7 . 5 t L VA c TOTAL cnjsr smn Mn'rfuri erto' V I Bcrs :■•-•=- =j:cs:-,-.-»c to-_^:-.j:— -e- LreLvtohts arc Uxe Fjtepfoes - -inrr urn acooun cnia - £1 00. Cheques over £100 are sx#dto7 ViCTVrigdejSdtefarsc& Carraoe chgrg^ (A)=C3 5 b, (B)^E50, (Cp£lD. {Dp£1 500, (E^=£1 B OO, (F]fCALL fifoi'i appfTK 3 fores tv srii'ccrg - ssa - CALL A1 goods suxzei to or Ssrdsfd Caviars cf Safe wicri c^i be ^ ctr wetste s-d urtess totoi; gjsranssd fev &j foejS AI ^jeranfess on a retan to bass bass At rifofos rested to change pnoss / speoncsddne'wAxu pfor redee. Otors slo> 3L re -re-. DsesjtsforvcS-CTte. Tcp CASH pfoss p ^ J for ajpfas goah A1 tiadacnaris, tet fenaress sfc sdro.^^torej Dsptey Eectorros 2002. E S OE- 1/2004 - eIsVidt cleftroniti 73 LI MS To book your website space contact Bernard Hubbard Tel (0)1242 510760 Fax: 0044 (0)1242 226626 BETA LAYOUT w,vw.pcb -pool. coni Beta layout Ltd Award- winning site in both English and German offers prototype RGBs at a fraction of the cost of the usual manufacturers' prices, BURN TECHNOLOGY LTD http: • femvJjumteo.com Distributors of a wide range of device programmers, package adaptors, test and soldering equipment. Order online and get free delivery on all orders over £30.00. COMPUCUT http:, www. com p u cu iter s iso m Computer Numerical Control from your home PC. Great for tricky jobs, and accurate repetitive work. We supply: - Software - Interface - Manual - Support Price £250 plus postage. CONFORD ELECTRONICS i 1 1 it 8 . • > Vi i'i '** .cp n tor de i e lt-go* u ^ lightweight portable battery/ mains audio units offering trie highest technical performance. Microphone, Phantom Power and Headphone Amplifiers. Balanced/unbalanced signal lines with extensive RR protection. DANBURY ELECTRONICS http : wv™ mc-h .demon . co . u k/trart sfo rniersiitm l Here you will find our mains and output transformers in Mike Holme's range of valve/tube amplifiers (PP & SEi. Also circuits, parts lists, chassis, advice. WF. W-PWL’ H spm . DEBUG INNOVATIONS UK h tip:/ 7 mm detiuginn ovat ion s.com introducing hassle free prototyping * RF / Analogue * High speed digital * Surface mount ■ 0.1" grid * Power planes * Unique patch architecture Forget custom PC8s, start your project now! EASYSYNC http ://vvw r vV.ea sy sy no .co . EasySync Ltd sells a wide range of single and multi- port USB to RS232/RS422 and RS485 converters at competitive prices. ELEXOL PTY LTD http: Vwv.w.eiexot.cam Developer and manufacturer of * USB Development Modules, * USBMOD Series, * USBIQ24 Digital Input Output Module. * MP3 Solutions. * MP3MOD4 Module. Distributor Inquiries welcome. ELM ELECTRONICS h tip : v, \\\'L el tn el e cirbn i cs ,c o m Offering a variety of unique and low cost integrated circuits for hie experimenter. Secure ordering via the web site with worldwide shipping. ELNEC ;avw. elnec.com * device programmer manufacturer * selling through contracted distributors all over trie world * universal and dedicated device programmers * excellent support and after sale support * free $W updates * once a months new SW release * reliable HW * three years warranty for most programmers ERVAN INTERNATIONAL Co. http:/ www.f rvan-inljEom Power Electronics and Solar Energy Design and Consultants. Also offers; Discount prices of: * Ultra Bright LEDs * PC 8 LED Cluster Kits * Laser Pointers * Solar Modules * Batteries FOREST ELECTRONIC DEVELOPMENT http: 'wwYdbffid. co.uk FED supply PIC programmers, Basic modules, and development software including a PIC C Compiler. 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Higher National NVQs, GCSEs and Advanced Qualifications), Also Technical Management and Languages. MQP ELECTRONICS h ftp : w vay. mq pels ctro nics ,co . u k Leaders in Device Programming Solutions. * Online shop * Low Cost Adapters for all Programmers • Single Site and Gang Programmers • Support for virtually any Programmable Device NEW WAVE CONCEPTS ntto: vnwr.new-wave-c^€spt3,co Software for hobbyists: • Livewire circuit simulation software, only £29.36 • PCB Wizard circuit design software, only £29.36 Available from all Maplin Electronics stores and wvAv.maplin.co.uk PEAK ELECTRONIC DESIGN LIMITED vA’Av.psakelecmuk Cool component test gear for your passives and semis. Instant identification, measurement and validation. Connect anyway round. Trie Peak Atlas family starts from £59. POND ELECTRONICS h ito: i v m vv . oo no. .8 tel +353-1 -821-5060 fax +353-1-820-9384 Innovative systems for PIC development & embedded applications. * pF lash 876 • PIC C Compilers & Programmers • MicroStack • Basic Stamp * Custom development Service QUASAR ELECTRONICS www fl u asarO edron i cs.co m Over 300 electronic Kits, projects era ready feu It units for hohm education and industrial applications including PIC/ATMEL programming solutions. Online ordering facilities. Tel: -44 (0) 870 246 1826 Fax: +44(0) 870 460 1045 Email: sale5@QuasaiElectmnEC3.com ROBOT ELECTRONICS http:/Avww.robobeleckon ics. co.uk * Ultrasonic rangefinders * Motor H-Bridge controllers * Magnetic Compasses ■ RC servos and controllers * PIC programmers and components » Electronic Design/Development and Manufacturer to industry SPICEAGE AND SPICYCLE htipidwv/v^Lspicsage.coMi SpEcycle circuit design program (schematic drawing, well-featured PCB drawing, Spice-Age simulation). SuperRIter digital and analogue filter sy nth es is and th< \ \ , >?& a tfrttrrr# optimisation. Download a oitl# Spicjclc free working evaluation and enjoy software renowned for iis high quality at prices that make it seem like Christmas all year round. Make contact with Those Engineers (020 8906 0155), real engineers, who will understand your needs. TECHNOBOTS http: w mv.technobots.c o.u k Welcome to Technobots - the one stop shop especially for the remote operated robot builder, radio control and engineering hobbyist TELNET http: /vwaw tel net. uk.com The site shows graphically Telnets 'wide range of quality second-user test and measurement equipment, including oscilloscopes and spectrum analysers. ULTRALEDS hap: //www.ultraledsmuk tel: 0871 7110413 Large range of low cost Ultra bright Teds and Led related lighting products, Major credit cards taken online with same day de patch. USB INSTRUMENTS http: • www. usd- iiisfru me nis.com USB Instruments specialises in PC based instrumentation products and software such as Oscilloscopes, Data Loggers, Logic Anaiaysers which interface to your PC via USB. VIEWCOM http: . ''/Av.v.viewQoin. f9.co.uk tel: 020 8471 9338 fax: 020 8552 0946 • Mall Order supplier of: • integrated Circuits and Components. • Kit and parts for Elektor projects, • Transistors. FETs, Capacitors, Resistors, Crystals, etc and hard to find devices. Viewcom Electronics, 77 Upperton Road West Plaistow. London E13 9LT Elektor Electronics have a feature to help customers to promote ihctr websites. Net Links - a permanent feature of the magazine where you will be able to highlighi your sire on a regular basis. - For just £ i 20 + VAT (£10.90 per issue for eleven issues i Elektor w ill publish your company name, a 25-word description and your website address. - For £300 + VAT for the year '£27.2^ per issue for eleven issues i we will publish the above plus run a 3cm deep full colour screen shot from your site. Places are limited and spaces will go on a strictly first come, first served basis, please fax back vour order tod as : «■ ■ r i I i 1 i i i I i i i J i i i i i t t I [ ] i I t i i t ! h I w ish to promote my company, please hiKik my space: ■ Text insertion only for £1 20 + VAT * Text and photo for £300 + VAT NAME: * ORGANISATION: JOB TITLE:....... ADDRESS:. - - ' r--ri ■ - *■ - PEL: PLEASE COMPLETE COUPON BELOW AND FAX BACK TO 0O44A 0)1242 226626 COMPANY NAME WEB ADDRESS 25- WORD DESCRIPTION.,, ------- p -'F - 1 1 r i i i t i i t i i i i t p.*-S >- + -g 3 -*« 4 * --------- . - - - - - - - -TP- Tr IILlCTI§©!A3fl(S IfWGWIMgTg Only one magazine tests its projects and circuits in its own lab before publication - Contact: Worldwide Subscription Service Ltd, Unit 4 Gibbs Reed Farm, Pashley Road, Ticehurst TN5 7HE Telephone: [+44| (0) 1580 200657 Fax: (+44) (0) 1580 200616 Or visit our Website: www.elektor-electronics.co.uk hLr.TJlT $fx2£=i •••=? ■ r:v- TV Eii: Portabl OSCILLOSCOPES Special Offers :: Just In ... ■ ■ TEKTRONIX ■ r 2445 A . !- 4Ch 150MHz Detoy. CuretW 3 etc. Suppfed with 2 TeDslrtkTk probes. 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A±fe- Fznznin Ssm £123 HP, !^:-U tf. 1 - fisaaes tot K - DMAtl 717 SU£4 STAR ETr-rTOfl 2&I& fSTKSEB fee eiKJ-2WHl E14-I :... :. L 1 - HP- SHEA SaeSiT TzfLKlttE. _ CtSU HP- 55573 Sjn S^ fes 5 1-2CK1H: £2543 CO- Aim $nilCH 1 SEHZ _ ni 3H Cii-n : £11 Radio Communications Test Sets y.Lj ;:*. ll;; r :-v i son AfiicvT : ■ ■■ yj?.’-; Lll’LJ-irdEr-L^ SjiD ETaF 110 WYKEHAM ROAD, REA01HG, BERKS. RGB 1 PL Stephens: <01 1B> 9262041. Fa.v (OIIS’i 9351655 www.stewart-of-reading.co.uk Used Equipment - GUARANTEED. Manuals supplied. Inis is 3 VERY SfiLAU. S^APtE OF STOCK SAE c? Tefepfiene tor liiix P^sass efeck avaMsSj MqG ordering. C ARHlAfiE sfl anils OS. VAT Id be added Id To te! of fkeds aid Cair-sge. UjJ ELEKTOR CD-ROMS RRP £16.25 (U5$28.75) The CD-Elektuur/Elektor 2003 CQ-rom contains all articles, with the exception of the news columns, published in Elekfor Electronics volume 2003. Using the supplied Acrobat Reader program, articles are presented in the same page layout as in Elektor Electronics magazine. To find expressions, the extensive search system on this CD-ROM allows you to scan previously published Elektor AnnualCD-ROMs. • print PCS layouts with up to 600 dpi resolution; • adapt PCS layouts with a drawing program; • quickly find articles, components, subjects, and so on, from monthly contents lists, the year index (on subject basis), or on the basis of titles, words, and components; • transfer diagrams, illustrations, PCS layouts, and text, to other pro- grams. • HTML overview for MacOS and Linux users • New! Now includes DtskMirror to run multiple year volumes from hard disk. viUDli Zv-HUjA MS 9 Order now using lhe Order Form m (he Readers Services section in (his issue Elekfor Electronics (Publishing) 0 P.0. Box 190 * Tunbridge Wells TN5 7WY ° England. Telephone +44 (0) 1580 200 657 • Fax +44 (0) 1580 200 616 ^L-S^TTlciLLTleS IHe E LECTIO ?JiC5 A CCMLim* MAGAllNI j-" . , j m See also www.eleklor- eledronics.co.uk Mi ■F 1 76 stellar stedronics - -4/2004 readers services Please Hole mr;=4 @ ^ y, - \tc~ the z .t p::t of tr* Pi&fsfeafaT wstj&s es ... 0&*-iti55 £?= s$S-: ; 5d fc-' :-= zg.tt etz :- r resc-rs - ~:-j1 ■ ’t" tt sc:=k x uss EVERGREENS EEaklor Electronics Help Disk U.'z- iVr-dOA-s lE^.Pn 8-15 14.45 Elektor Electronics llem Tracer 19BS-2QEJ2 C40C63-11 r--’-.r--z - i ■ Vl • • ,-4 E- . fTy C ■ B-15 1435 Medium power HEXFFT ampltHer (December 1993) 9 3D 102-1 F£3 10^0 19.25 Universal Pfulolyping Boards upas-t PCc 245 4.30 UFB S-2 2 PC d 5 440 7.25 4?Cas 5-55 11.55 GENERAL p- ■ - jc-z -- . - :-: r: e - C E : s: ; -e : - ee - ? tir : r : io>*. HD Vs EFFOVj P-.? GAls - r: (feSsSs fee prafeeb Krficfi Isw appesrad fe ffetfep Bec&mcs ms y is afcsraJ osvig ie Onfer Toma priifcd ■::::- ■ - r7 : , - 1 : - t-t ; .=■7 cv": -: v f. * ms for mg&ig a PCS ntfeh '5 nof *rafetsfe re 1 t f -- --- 7 ~ - r = - = 1 r : ? - -< '- 7i ust -■= ‘?-nd JT t”r "7 7 il~" iTt I 7 tPR&Vr t-X PAis. lEiFlih VACHs ^7: e rrftiQcosimfla’a ipri sidled tea^vdglanfe^ Press and asm daofe&cis sfeptf fe cEsn-ji. TTa? puth Gfcseije pries uShag prior rafr " ztxr Friszs er.i it™ tfgscif'tiiHis sExrarn ters icjsr- Inin iot in pterins iUKl L £ D E PAST ISSUES Pist issoes. rl sfttMXd b£ Gnfefid btkm Wcrlcfrids SsisicriptiGti Eertkx Lid. Unit 4. GtiSs Retd ?i— Fii-:=T Read, TlCEHUHST THS THE, EngE--; tde'fcas£ 1^441 15E0 2 l 5557. hi !-«j. 1525 2i:Slc err?j] wnisl ■Tiss.fs^oiLia.uk. Friz; ■:■ zzz: ’is.ci 75 iri" J_jy Au5c.it L~z in' ireto uSa^ postage faff &5gis oc:.:i le L- '5 l, 1 , ±t &p|; £$JQ j=c m=i Eyrof*?); £6.10 famaS cefiafe EtyOpe^ Rfter? of put Jrif/Augatf and Osssnie? a _ =-= rnpi-,<&Tj postage fef ssttfe copfes. sts £6.55 itfit anti Eire}; £7,35 {smirf Europe): sad £6.45 {armsi cX-loe :^2p7 PAST ABTICiES Trr ■■:■-■■ ■ " ;n ;ii: irrCc? 5;.:i:r co - '?:loes £:■'_■■ i aid Ac^Tffi5irS7f¥ 046^5. (61560} ^1555?; fei. liCoia “1l :£ :. _►. no. 331 APRIL 2004 Drop-in Microcontroller Board m 020*4^ FCfi 8-60 13-20 u 1420148*11 D^k. ist-. -i yc -Mt 4-90 3.65 Pandora's Sound & Music Box .3; 330402-1 PC 3 10 50 13.75 .1. Q3C4G2-1 " I i h : _ rce i r ai : •:• :•= f 4 e 4-90 £65 030402 41 FlC 1 BFS 7 V H prog “ “ t e-= 20-55 E-5.1 _’ VHF-low Explorer g 02C41^t ?C3 o-m 15.5Q No. 330 MARCH 2004 Build Your Own 0 R M Receiver 3_. 03D3S5-1 PCB 9-10 16.10 S- 02 0 3-5 5-1 " h :■. D F e^e program 4-SC 3.65 Code Lock @ 0204344 PCS 000 16.95 g 02 l:434'j1 D.W SC^'Ct ?• 74* COiE ' f-S 4^0 2.65 0254344 1 Rc 1 EFS4 A - 4 F. pfCCE^^T^j 14-70 Handi-orv CPLDs (2] @ Q3DQ52-1 FCE 8-90 15.75 5 GjC052-11 SbJTl'/se 4-90 8.65 Sj'jQ52-ti EFV712SSLC54-T5. crc.:n--n=-j 33-40 59 10 hloliichajinel Failsafe for Radio OcnlrolfesJ Models % C 2C 852-1 1 C E 4 EE -TE -EL'dE f E 40fO B.m 020362-4 1 AT59C 52-24 jl pf o •^raaxncd 3-70 15.40 Mullitunction Frequency Meier @ 0.53155-- PCS 9-35 16.55 ■a: 055135-11 D^3 l praiid sotiMre 4^5 0,65 u32 1 3t -41 AMOSES' 5 - J C - C r-"-T Tin :: 7-95 14.Q5 No* 329 FEBRUARY 2004 Digital Alarm Clock 3 030396-11 D-.5>. RC 50=. rce Lrjdnjr ;oc-i 4-9D 6.65 &3«9fr4 1 PI Cl of 54-04 ;=. pro^airer^f 15-20 26 90 iAccess g 020453-11 Dye Set 5(tsais code aid tafftuf software 7-50 13S0 S2016341 AT65S5252*1ZPC. ctt-tte-: n-so 24.60 Simple 12-lo-23flV Povrer Inverter @ D20435-1 PCS S-50 15.05 Touch-controlled Svrileh S 030214-1T C4- RC sojTtc ecce 4-50 £.65 03 52: i-i : FiC 1 2C 50 140 4 1C 1 t - 1 ■ 615 10 00 No. 328 JANUARY 2004 B4-K &DC552 Flash Board .§ 035C42-1 PC 5 035 16.55 ,E Q15142-T1 &!:■■ tr=:*;. peo!t« sate?* 490 6.65 03X42-21 2S3010. p:c^TTiT£i 1000 17.70 03 V42-34 GAL : £. mi5W. pnsraiunasd &10 10.56 Climate Logger @ 03&S76-1 PC a 775 13.70 g[ '333075-1 1 0A* ViuTCferVa SD?fiVifB 490 S.65 FMS Flight Simulator Encoder 3 050063- : FCB 1020 13.05 030055-41 ETLPlTq/B’L pr-v^TTEd 17415 ■■015 LED Roulette I. 030163-1 PC 3 17-90 31.60 i 3: : 1 1 3- " J C jJk e :_t e zrd f 5 b e 4-90 £.65 030153-41 59C2051 -12FC :e; e :.: 5-05 14X5 Multi-event Alarm Clock 3 : 1331 4- 1 1 C ILI. - ■ : - - 1 ■" is 450 S.6-5 02033 4-41 AT69C20 51-1 2FC . : rog rir.T^ t to 10,50 Stepper Motors Uncovered 520127-11 P.C16F -573-20 3? 19-10 33 J0 No* 327 DECEMBER 2003 FM Rentote Control Transmiller & Deceiver •© 034044-1 PCS 10-20 IBOq LED Chiislmas Decoration m 050157*1 PCB £ 7-55 US $ 13.15 PB7LPC76x Programmer @ 0503 1 3-1 1 0 = *l fn&je :t software 490 £.65 Project Timekeeper S 02635X11 [fek skjis L c&iefites 4-90 02O55O-1 1 p; C 1 EF 24-1 G ?. et-e-t- t-e j 1215 3355 Stepper Molars Unearned (2| © 020X7-11 G e ■ . efjL 3C z c r jiz = :e 4 90 865 Universal Ctnck Generalar g 02033541 D.ea 5v_vr K'ife ffe 490 S.dS Wireless RS232 Link @ 0307644 PCB E-70 15 40 No* 326 NOVEMBER 2003 Precision Measurement Cenlraf © O30CQT4 PC S 8-70 15.40 No* 326 NOVEMBER 2003 Rev Counter for R C Models m 0241114 PCS 17-50 31 [C OX-4 1 1 1-1 " D E+_ El _ [E ■Z. r ’E I E EZ 4^3 £ £5 0 34111-41 5 9C205 142PC : J . :iat fl-85 15.66 Running Tert Dispiay g 0204974 s C%;V mv?ce A:d r.-s* ccefe 4-92 5.65 USB Analogue Converter @ 02O374'i PCB 7-65 13 50 I 020 3T---“ “ n.-:2 - : ■ i-r 0 ~eev.e ictr^LT 490 8.65 020374 -- ■ RC1 60 765. p TETTTed 13 55 2345 No. 325 OCTOBER 2003 DDS RF Signal Generator 3 050509-“ PCS gcrsrclDf 11-60 20.65 @ 020299-2 FC6. cetT', supply 1510 2145 02 O2034 ■ 47005-55 1 5 -5 PC . prcc ; it "n=d 30-55 54Q5 Minimalist Induction-Balance Metal Oelector @ 020290-1 FC3 S-95 15.85 Xllinx PROM Programmer t, 010163-11 SettA-sre 490 6.65 No. 324 SEPTEMBER 2003 ATV Picture Generator 3; 020295-1! 077 sauna 6 rsK coda f."as 4-99 5.65 02029541 AT9Q58515^PC. pro^rsmmed 15 20 2590 020295-42 AT 95S1 200-1 2FC. pmgrLTmsI T3-90 24 tO DTMF Remote Telephone Switch @ 020294 “ PCB 11-65 2060 g 020294-11 [ L<. i-'eX:: :.: f T,vE r E 490 6.65 ' 02059441 F Cl 6F84A-20- 0 CiTjOS.--^ 1470 25.60 LC Display with 12 C Bus @ 03.XXO-Z PC 3 7-S5 13C elektor-etectroniGS, m uk 78 elslrtor ciedronia - 4/200-1 p riSc 'EETi d this CrGST SO M (sw reverse For conditions) Elektor Electronics (Publishing} P,0, Box 190 Tunbridge Weils IMS 7WY ENGLAND M: (+44) iO)15fiO 20 D 657 Fa*:( + 44) (0? <580 200 516 nte m el: v, av* . c ! 1 e kior - s ' s c l/o n ics . c o .u k *U$4 £□££&&& restarts mar P«t are not obliged lo) use $ prices, Sii} Send tnc onfej romitu: OSd CoSorcy Sound La*. 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Subsciphons cannot be cancelled after they have run for six months or more, January 2004 SO sfsklw tlfidrflnta - 4/2001 pcb layouts D rap -in M icrocon trailer B card 020 1 2 8 - 1 ( soldo r s ide) Drop-in Microcontroller Board 020 148-1 {component side) Pandora 's Sound & 'dusk Box 030422 - 1 Low-Power LED flash 030345- l 4/2004- eiektor dedronics 81 leak preview next month in elektor electronics Digital Anemometer with Wind Direction Indicator Apart from the use of a F1C 1 6F876 micro- controller in combination with □ digital readout, this project is special because the wind direction meter dees not employ a vane or similar Instead, she wind direction is derived from the rotational signal sup~ plied by the wind speed sensor] Sensors The main feature in ihe May 2QQ4 issue will be "sen- sors and include subjects like - news from I he Massachusetts Institute of Technology (MIT) on polymer sensors and their miniaturization; - developments and trends; - insight on d background: tyre pressure sensor and systems. — T I T Stepper Motor Control Lois of practical advice and hardly any theory — taking it step by step using a driver board and example pro- grams for popular software development platforms. Also**. - Infrared mc-dule for microcontrollers and PDAs - Voltage control for SMPSUs - Quartz: crystal oscillator - MAX7CKX) prototyping board - Room thermometer - Canon AOS cameras go wireless TV Commercials Killer for VCRs TV commercials are o nuisance to say the least particularly if they are recorded with □ film or a spoils programme. It doesn't have to be like that. Our TV Commercials Killer analyses the broadcast signa; and responds the moment the station logo disappears (or appears again) — controlling the VCR by means of infrared (as with the remote control). RESERVE YOUR COPY MOW! Tbs Ms. 2004 issue g:ss n ssh c-n Fricoy 22 kf\ 2594 (UK diitriwlfcn anfyl UT' subscribers vrill receive ibe mopitne o few days before this dole. Article titles ond mopiine contents subiett to change. NEWSAGENTS ORDER FORM SHOP SAVE / HOME DELIVERY Please save deliver one copy of ElektoT Electronics magazine for me each month 3kH1.0 ■ • «■ * * ■ * -B- * -■ m m lie * m m * ■ ■ ■ ■ ■ m mm mm m, mmmmmmmmmmmm Ad dr e ss * *■■■-¥ » » >. « « » * * « » « « « » »«■» ■» * * Pnqr rorlp* Tslcpbon^. ..................... .... . i < . ■ . . . i n ai-p ■ ■im-* t-lt %i W r m m m m m m m m m m m a u M # # * # + + + d- i- a- ■* r ■» «■ -a I -» * -m -■ m m m m a m i b « A: Signature: ..a........................ . elektor electronics Please cut out or photocopy this form, com- plete details and hand to your newsagent. Elektor Electronics is published on the third Friday of each month, except in July. Distribution S.QR, by Seymour (NS). Beta Layout. Net links avav, u zt-::-: '.nsm Bum Technology LID, ’Vet Links wv.v tumtec cum ... CMS . , . w^cms.ukcom .... Compueut. Hsi Links * Wf.\vcGm£uZii:?&i.C2'v .... Contend Electrons, Kti Links . . :m™c«w7/b tfe.ee . Cncklswocd ....... ........ Danbury tat links w j ■, y,- c -/?. € f man. co.uk Debug Inn orcSens , f l et U n.ks . v e r : u g r - :■ .a ■ i s. c am . Display Bectnmies Av,\\',.c:SieUc.ui. Easysync. tat Links _ . ,r,v, easysnic coE < ....... □emf Net Links .lyww.etexo/, com ELM Electronics, lie: Links. ,.v,v. e me "iym : : Elnec, Met Links ................... .wwive/raec-eciTJ . . Enitovi iV.ViV z~nisvi.CD.vk . . Ervan, tat Links JAViWtr, in - ixlcnm Eurockeiits ................... Forest (let Links ...... .... Future Technology Devices, tat Links Futuriec, tat Links Hammond Becironics. list Links , . . v,vt:.rs j ' upxom . . . .WVM fiOfeti.CQMk .......... . . JtWfiVft&CKS.CQ) 7 ) ......... avmM- riev.c &™ ......... . . . .ih vvv, rrammordmlg. com ViYrt./ipWlcon* ... Ubcenier ava vfebcM&CQL *: ....... London Electronics €'o'"ege Met Links . . jaw. 'bc.C’c .J Ma tnx 1 . 1 r ultim ec 3 Ltd ............... , v, vj : m sin > mu in ~ e-r'-a. c s. .. ■ Milford Instrurnents ... nst.denan.cQ.i:* . . . Index of Advertisers 26 , 74 MOP Monies, ftet Links - WM-.Hifme^ctrcmcs.ai.Lk 74 74 37 74 .......... .74 ... .72 27 t 74 74 .74 ,74 .74 73 26 , 74 ....74 ....74 . . . .74 26 . . . .64 ....74 ....67 Net Links ............ .74, 75 Mew Wave Concepts, Met Links ...... m. ~6.v-wi. e-co ^pis.com 74 MiKnUBf One Systems .............. .iv'jvjv.nt mbtranerom ........ ... .27 PAG.U .WAV/.pagm.cQMk .2 Peak Be c ironic . Met Lin ks aya v , . n sa ‘.eiez.coMk 74 Pico AYAWAfr^aq.Ciom . ... .51 Pond Electronics, fiefc Links .......... AVAw.pood.ie ................... .74 Quasar Electronics. Mel Links mM.qitasaretectmits.com .75. 33 Robot Electronics, fM Links A'Aw.rQhm^iectmmcs.czMk 75 SpEceage and Spfcycie, Net Links .WKW.spkc3gB.com ........ 75 Biswari of Reading .wm.stemrt-Qf-mtfmg.coMk .76 Testing Sots, Met Links AYAwAecimotots.QQMk 75 Tetiret, Met Links ... . . .cum .75 Ultraled3, Wet Links ..... .\Y,w.ultfc!e8$mv< ........ 75 USB instruments. Mel Links ...... v . it- rstn tnsrfcxcm ... .75 Vera Technology aiwa vBmtKcnm . . ,67 Vjewcorn, M Links ........ ... .•Avw.Y&iYCttfii ffixmk .75 ADVERTI3 11 lG SPACE for tt-.b ssue o' IS fife 1 / 2004 may be resEreed not Eater than 21 April 2004 with Bakior Et^troajcs iPuKstiTg. Acyerdserrent On :a - 3 Crescent Terrace - Cheltenham GL5G 3PE - Eng 'and - TE'ephona 01242 510 76fl - Fax U1242 226 626 - e^naS: 5&jnjnfnubteteta!iADnBne.co..uk to wfwm afl correspondence. copy Instructions and artwork should be addressee. 82 e’eVt-sf ebcticjiks - 4/2304 . Quasar Electronics Limited PO Box 6935, Bishops Stortford r CM 23 4WP Tel: 0870 246 1826 Fax: 0870 460 1045 E-mail: sales@quasarelectronics.com Add £3,00 PSP to all UK orders or 1st Class Recorded - £5, Next Day (insured £250 J - £3, Europe - £6, Rest of World - £1Q (order online for reduced price UK Postage}. We accept all major crediLTdEbit cards. Males ehequesfPO's payable to Quasar Electronics. Prices include 17.5% VAT. Call now for our FREE CATALOGUE with details of over 300 kits, projects, modules and publications, MAIL ORDER ONLY. VISA I , I : . Jl-.l 1 IQ QUASAR electronics i©fi CREDIT CARD SALES T1 Halpfrg swra® ff» cxraacftra/ Motor Drivers/Controllers Here ere just a few or our controller and driver modules for AC. DC. un ip o la bipolar stepper motors and servo motors. See website for full details. DC Motor Speed Controller (5A/10QV) Control the speed or almost any common DC motor rated up to 1 C0V/5A. Pulse width modulation output for maximum motor torque at all speeds Supply: 5-15VDC. Box sup- plied, Dimensions (mm): 6GWx100Lx6QH. Kit Order Code: 3067KT- £12.95 Assembled Order Code: AS 3067 - £19.95 MEVH PC / Standalone Unipolar Stepper Motor Driver Drives any 5, 6 or 8-lead unipolar stepper motor rated up to 6 Amps max. Provides speed and direc- tion control. Operates in stand-alone or PC- controlled mode. Lip to six 3179 driver boards can be connected to a single parallel port. Supply; 9V DC. RGB: 60x50mm. Kit Order Code; 3179KT - £9.95 Assembled Order Code; AS31 79 - £16.95 PC Controlled Dual Stepper Motor Driver Independently control two unipolar stepper motors (each rated up to 3 Amps max.) using PC parallel port and soft- ' 1 1 iVv"-- i ■ i 1 llllk 7 v 8 i ^ - ware interface provided. Four digital Inputs available for monitoring external switches and other inputs. Software provides three run modes and will half-step, single-step or man- ual-step motors. Complete unit neatly housed in an extended D-sheil case. Ail components, case, documentation and software are sup- plied (stepper motors are NOT provided). Dimensions (mm); 55Wx7QLx15H. Kit Order Code; 31 1 3KT - £15.95 Assembled Order Code; AS31 13 - £24.95 NEW! Bi-Polar Stepper Motor Driver Drive any bi-pc far stepper motor using externally sup^ piled 5V levels for stepping and direction control. These usually come from software running on a computer. Supply: 8-3 GV DC. PCS: 75x85mm. Kit Order Code; 3T58KT - £12.95 Assembled Order Code; AS31 53 -£26.95 Most items are available in kit form (KT suffix) or assembled and ready for use (AS prefix). Controllers & Loggers Here are just a few of the controller and data acquisition and control units we have. See website for full details Suitable PSU for all units; Order Code PSU2G3£9.95 Rolling Code 4-Channel UHF Remote State-of-the-Ari. High security. 4 channels. Momentary or latching relay output. Range up to 40m. Up to 15 Tx's can be leamt by one Rx (kit in- cludes one Tx but more avail- able separately), 4 indicator LED *s. Rx; PCS 77x85mm, 12VDC 6mA (standby). Two and Ten channel versions also available. Kit Order Code; 3180KT - £41 .95 Assembled Order Code; AS318Q - £49.95 Computer Temperature Data Logger 4-channel temperature log- ger for serial port. a C or’F. Continuously logs up to 4 separate sensors located . 200m+ from board. Wide " range of free software appli- cations for storing/using data. PCB just 38x38mm. Powered by PC. Includes one DS 1 820 sensor and four heade r cables. Kit Order Code: 3145KT - £22.95 Assembled Order Code: AS31 45 - £29.95 Additional DS1 820 Sensors - £3.95 each NEW! DTMF Telephone Relay Switcher Call your phone number using a DTMF phone from anywhere in the world and remotely turn on off any of the 4 relays as desired. User settable Security Password! Anti- Tamper, Rings to Answer, Auto Hang-up and Lockout, Includes plastic case. 130x110x30mm. Power 12VDC. Kt Order Code; 3140KT -£39.95 Assembled Order Cede; AS31 40 - £59,95 Serial Isolated I/O Module PC controlled 8-Relay Board. 115/250V relay outputs and 4 isolated digital inputs. Useful in a variety of control and sensing applications. Uses PC serial port for programming (using our new Windows interface or batch files). Once programmed unit can operate without PC, Includes plastic case 130x1 C€x30mm. Power Supply: 12VQC/50OmA. Kit Order Code: 3108KT - £54.95 Assembled Order Code; AS3108 - £64.95 Infrared RC Relay Board Individually control 12 on- board relays with included infrared remote control unit. Toggle or momentary. 15m+ range. 1 12x1 22mm Supply: 12VDC Q.5A Kit Order Code: 3142KT - £41.95 Assembled Order Code: AS3142- £59,95 PIC & AT MEL Programmers We have a wide range of low cost PIC and ATMEL Programmers. Complete range and documentation available from our web site. Programmer Accessories: 40-pin Wide ZIF socket (ZIF40W) £15.00 18V DC Power supply (PSU215) £19.95 Leads: Parallel (LEAD 10 8) £4.95 / Serial (LEAD76) £4.95 / USB (LEADUAA) £2.95 NEW! USB 'All -Flash* PIC Programmer USB PIC programmer for all ‘Flash’ devices. No external power supply making it truly portable. Supplied with box and Windows Software. ZIF Socket and USB Plug A-A lead not inch Kit Order Code; 31 28KT -£29.95 Assembled Order Code: AS3128 - £39,95 Enhanced : NPICALL !r ISP PIC Programmer Will program virtually ALL 8 to 40 pin PICs plus a range or ATMELAVR, SCENIX SX and E EPROM 24C de- vices, Also supports In Sys- tem Programming (ISP) for PIC and ATM EL AVRs. Free software. Blank chip auto detect for super fast bulk programming. Requires a 40-pin wide ZIF socket (not included). Kit Order Code: 31 44KT £54.95 Assembled Order Code: AS3144 - £59,95 ATM EL 3 9 xx xx Programmer Uses serial port and any standard terminal comms program. 4 LED’s display the status. ZIF sockets not included. Supply: 1£MSVDC. Kit Order Code: 31 23KT - £29.95 Assembled Order Code; AS 31 23 - £34.95 NEW! USB & Serial Port PIC Programmer USB Serial connection. Header cable for ICSP. Free Windows software. See website for PICs tsupp Dried- ZIF Soeket/USB Plug V A-A lead extra. Supply: 18VDC. Kit Order Code: 31 49KT - £29.95 Assembled Order Code: AS3149 - £44,95 www.quasarelsctroniIcs.com H Secure Online Ordering Facilities Full Product Listing, Descriptions & Photos Kit Documentation & Software Downloads 1/2001 - deleter elediKtics 83 The Co ete Electronics Design System *.,»,** ^>i#i lit* >u*-i mwtewem \ - - i »‘iiin»iiirim fthematrc 1 1 U 1 1 i lti rrrT V JVr Simulation Auto Placement m W- — » »mix< uii nrr - _ «•- Schematic & PCB Layout : J * w I _ Auto Routing j*i j • Powerful & flexible schematic capture. • Auto-component placement and rip-up/retry PCB routing • Polygonal gridless ground pianes. • Libraries of over 8000 schematic and 1000 PCB parts. • Bill of materials, DRC reports and much more. Mixed Mode SPICE Circuit Simulation Berkeley SPICE3F5 simulator with custom extensions for true mixed mode and interactive simulation. 6 virtual instruments and 14 graph based analysis types. 6000 models including TTL. CMOS and PLD digital parts. Fully compatible with manufacturers' SPICE models. • Drag and drop toolbars. • Visual PCB packaging tool. • Improved route editing. • Point and click DRC report. • Multiple design rules (per net). • Multiple undo/redo. Call Now for Upgrade Pricing - Proteus VSM - Co-simulation and debugging for popular Micro-controllers Supports PIC, AVR, 8051, HC11 and ARM micro-controllers. Co-simulate target firmware with your hardware design. Includes interactive peripheral models for LED and LCD displays, switches, keypads, virtual terminal and much, much more. auur ce level debugging for popular compilers and assemblers from Crownhil!, IAR, Keil, and others. www. I a be enter, eo. uli info @labcenter. co. uli Tel: 01756 753440 Fax: 01756 752857 Electronics 53-55 Main Street, Grassington. BD23 5AA