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POPULAR FEATURES . VOL. 32. No. 11 NOVEMBER 2003 Cover illustration by jgr22 www.epemag.wimborne.co.uk EPE Online: www.epemag.com Projects and Circuits PIC RANDOM L.E.D. FLASHER by Andy Flind 740 Enjoy the fun of an interesting and attractive pattern display INGENUITY UNLIMITED – Sharing your ideas with others 746 Three-Component Metal Detector; Emergency Light; Power Supply Tester ANYONE AT HOME? by Owen Bishop 766 Logically deter those shifty characters eyeing up your house! Another Top Tenner project CARDBOARD CLOCK by Michael McLoughlin 778 An intriguing and novel way in which you can tick-off time passing! PRACTICAL RADIO CIRCUITS – Part 6. Single-sideband and 793 direct conversion by Raymond Haigh Another superb receiving system for the set builder and experimenter Series and Features TECHNO TALK by Andy Emmerson 748 Why is lightning so potent, and can you protect your gizmos? TEACH-IN 2004 – 1. At the Beginning by Max Horsey 750 The first feature in our new 10-part tutorial and practical series – how to apply electronics meaningfully NEW TECHNOLOGY UPDATE by Ian Poole 760 Floating Gate Analogue technology improves voltage reference devices CIRCUIT SURGERY by Alan Winstanley and Ian Bell 774 Long delays; cooling fans; more on SPICE; op.amp enlightenment PRACTICALLY SPEAKING by Robert Penfold 790 A novice’s guide to understanding semiconductor markings NET WORK – THE INTERNET PAGE surfed by Alan Winstanley 802 Oh for wireless webbing . ! New EPE Downloads site Regulars and Services EDITORIAL 739 NEWS – Barry Fox highlights technology’s leading edge 744 Plus everyday news from the world of electronics PIC RESOURCES CD-ROM 762 Invaluable to all PICkers! BACK ISSUES Did you miss these? Many now on CD-ROM! 763 READOUT John Becker addresses general points arising 771 SHOPTALK with David Barrington 777 The essential guide to component buying for EPE projects CD-ROMS FOR ELECTRONICS 786 A wide range of CD-ROMs for hobbyists, students and engineers DIRECT BOOK SERVICE 800 A wide range of technical books available by mail order, plus more CD-ROMs PRINTED CIRCUIT BOARD AND SOFTWARE SERVICE 803 © Wimborne Publishing Ltd 2003. Copyright in all PCBs for EPE projects. Plus EPE project software drawings, photographs and articles published in ELECTRONIC MANUALS 804 EVERYDAY PRACTICAL ELECTRONICS is fully Essential reference works for hobbyists, students and service engineers protected, and reproduction or imitations in whole or in part are expressly forbidden. ADVERTISERS INDEX 808 Our December 2003 issue will be published on A Thursday, 13 November 2003. See page 731 for details Readers Services Editorial and Advertisement Departments 739 Everyday Practical Electronics, November 2003 729 NEXT MONTH CHRISTMAS CHEEKS A Christmas, disco or party project with a difference! Instead of enhancing your Christmas decorations, it is designed to enhance . you! With recent advances in semiconductor technology, the maximum luminous intensity of red l.e.d.s has increased to several candelas. Now consider that human flesh is translucent to red light. Combine these two facts, and we have the basis for this project. The average facial cheek has a thickness of between one and two centimetres, and this makes it possible to “backlight” a cheek from the gums with a high intensity l.e.d., causing it to glow in the subdued light of a Christmas party or disco etc. The slimline circuit featured in this article is slipped between the gums and cheek, and is activated by the presence of saliva. Just think of the attention you will attract with flashing cheeks! VIRUS ZAPPER Mk2 Imagine, if you will, a simple battery-operated device capable of stopping the common cold and many other afflictions in their tracks. At the onset of a sore throat, say, the user would simply grasp a pair of electrodes, switch on, and in no time become perfectly well again. PIC NIM MACHINE Sounds like an impossible pipedream, doesn’t it. Yet this is the claim for the Clark Virus Zapper, versions of An ultra-modern version of the age-old game of which are widely available from internet sources. Many NIM. There have been many electrical or enthusiasts swear by its effectiveness, so it’s just electronic versions of NIM over the years since possible it does work, at least for some users. the Nimatron was demonstrated at the New The Virus Zapper is the invention of Dr. Hulda Regehr York Trade Fair in 1940. This PIC-based project Clark, an American lady who claims it can destroy all is simple to build, easy to play and has a manner of viruses, bacteria and parasites within the switched range of difficulty levels from easy-to- body. This project is an updated and improved beat to nigh-on-impossible-to-beat. It should development of the Virus Zapper we published in the keep everyone fascinated for hours at March ’02 issue which proved to be very popular with Christmas. readers. Build it and judge the results for yourself. TEACH-IN 2004 – PART 2 PLUS RADIO CIRCUITS – PART 7: THE SUPERHET NO ONE DOES IT BETTER DON'T MISS AN ISSUE – PLACE YOUR ORDER NOW! Demand is bound to be high DECEMBER 2003 ISSUE ON SALE THURSDAY, NOVEMBER 13 Everyday Practical Electronics, November 2003 731 Quasar Electronics Limited Add £2.00 P&P to all UK orders. 1st Class Recorded – £4. PO Box 6935, Bishops Stortford, Next day (insured £250) – £7. Europe – £5. Rest of World – £10. CM23 4WP We accept all major credit/debit cards. Make cheques/POs payable to Quasar Electronics Limited. Tel: 0870 246 1826 Prices include 17.5% VAT. MAIL ORDER ONLY. Fax: 0870 460 1045 Call now for our FREE CATALOGUE with details of over 300 E-mail: [email protected] high quality kits, projects, modules and publications. CREDIT CARD 00 88 77 11 SALES 717717 71687168 Helping you make the right connections! ABC Mini Microcontroller Board NEW! DTMF Telephone Relay Switcher PIC & ATMEL Programmers Currently learning about Call your phone number microcontrollers? Need using a DTMF phone from We have a wide range of low cost PIC and to do more than flash a anywhere in the world ATMEL Programmers. Complete range and LED or sound a buzzer? and remotely turn on/off documentation available from our web site. The ABC Mini Starter any of the 4 relays as Programmer Accessories: Kit is based on ATMEL’s desired. User settable 40-pin Wide ZIF socket (ZIF40W) £15.00 AVR 8535 RISC tech- Security Password, Anti-Tamper, Rings to Answer, Auto Hang-up and Lockout. 18VDC Power supply (PSU201) £5.95 nology and will interest Includes plastic case. 130 x 110 x 30mm. Leads: Parallel (LEAD108) £4.95 / Serial both the beginner and expert alike. Power: 12VDC. (LEAD76) £4.95 / USB (LEADUAA) £2.95 Beginners will find that Kit Order Code: 3140KT – £39.95 they can write and test a simple program, Assembled Order Code: AS3140 – £59.95 using the BASIC programming language, NEW! USB ‘All-Flash’ PIC Programmer within an hour or two of connecting it up. Serial Port Isolated I/O Module USB PIC programmer for all Experts will like the power and flexibility of Computer controlled ‘Flash’ devices. No external the ATMEL microcontroller, as well as the 8-channel relay board. power supply making it truly ease with which the board can be 5A mains rated relay portable. Supplied with box “designed-in” to a project. outputs and 4 opto- and Windows Software. ZIF The ABC Mini STARTER PACK includes isolated digital inputs Socket and USB Plug A-A lead everything you need to get up and experi- (for monitoring switch not incl. menting right away. On the hardware side, states, etc). Useful in a Kit Order Code: 3128KT – £29.95 there’s a pre-assembled ABC Mini Board variety of control and sensing applications. Assembled Order Code: AS3128 – £39.95 with parallel and serial cables for connection Programmed via serial port (use our new to your PC. Windows software included on Windows interface, terminal emulator or Enhanced “PICALL” ISP PIC Programmer CD-ROM features an Assembled, BASIC batch files).