Copyright Ó 2004, Wimborne Publishing Ltd (408 Wimborne Road East, Ferndown, Dorset, BH22 9ND, UK) and TechBites Interactive Inc., (PO Box 857, Madison, Alabama 35758, USA) All rights reserved. WARNING! The materials and works contained within EPE Online — which are made available by Wimborne Publishing Ltd and TechBites Interactive Inc — are copyrighted. You are permitted to make a backup copy of the downloaded file and one (1) hard copy of such materials and works for your personal use. International copyright laws, however, prohibit any further copying or reproduction of such materials and works, or any republication of any kind. TechBites Interactive Inc and Wimborne Publishing Ltd have used their best efforts in preparing these materials and works. However, TechBites Interactive Inc and Wimborne Publishing Ltd make no warranties of any kind, expressed or implied, with regard to the documentation or data contained herein, and specifically disclaim, without limitation, any implied warranties of merchantability and fitness for a particular purpose. Because of possible variances in the quality and condition of materials and workmanship used by readers, EPE Online, its publishers and agents disclaim any responsibility for the safe and proper functioning of reader-constructed projects based on or from information published in these materials and works. In no event shall TechBites Interactive Inc or Wimborne Publishing Ltd be responsible or liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or any other damages in connection with or arising out of furnishing, performance, or use of these materials and works. ISSN 0262 3617 PROJECTS . THEORY . NEWS . COMMENTS . POPULAR FEATURES . VOL. 33. No. 7 JULY 2004 Cover illustration by jgr22 www.epemag.wimborne.co.uk EPE Online: www.epemag.com Projects and Circuits PORTABLE MINI ALARM by Andy Flind 448 Covertly monitor your property and distinguish between loiterers and passers-by INGENUITY UNLIMITED – Sharing your ideas with others 458 Multiple Range Ammeter; Repeatable Logic Probe; Model Theatre Lighting Dimmer BONGO BOX by David Clark 462 PIC up the rhythm with our MIDI finger drum! EPE PIC MAGNETOMETRY LOGGER – 1 by John Becker 469 Logging your search for magnetic fields that might reveal hidden artifacts HARD DRIVE WARBLER by Terry de Vaux-Balbirnie 501 Monitor your PC’s hard drive activity from a distance Series and Features TECHNO TALK by Andy Emmerson 456 When it comes to standards, choice is not always a good thing! CIRCUIT SURGERY by Alan Winstanley and Ian Bell 461 Dual-rail power supplies; Superglue TEACH-IN 2004 – 9. Lock and Alarm Systems by Max Horsey 482 Continuing our 10-part tutorial and practical series – how to apply electronics meaningfully PIC N’ MIX by Andrew Jarvis 494 “Hello World” for PICs: instruction cycles, masks and clockwork l.e.d.s NET WORK – THE INTERNET PAGE surfed by Alan Winstanley 499 More on web search engines, plus a look at Gmail MAKING FRONT PANEL OVERLAYS by Andrew Martell 504 Making low-cost professional-looking front panel overlays using your PC PRACTICALLY SPEAKING by Robert Penfold 506 A novice’s guide to troubleshooting project construction problems Regulars and Services PIC RESOURCES CD-ROM V2 Invaluable to all PICkers! 442 A plethora of 20 “hand-PICked” EPE past projects EDITORIAL 447 NEWS – Barry Fox highlights technology’s leading edge 454 Plus everyday news from the world of electronics SHOPTALK with David Barrington 467 The essential guide to component buying for EPE projects READOUT John Becker addresses general points arising 478 BACK ISSUE CD-ROMS Single-source shopping for issues you’ve missed 480 BACK ISSUES Did you miss some issues? 492 CD-ROMS FOR ELECTRONICS 496 A wide range of CD-ROMs for hobbyists, students and engineers DIRECT BOOK SERVICE 508 A wide range of technical books available by mail order, plus more CD-ROMs PRINTED CIRCUIT BOARD AND SOFTWARE SERVICE 511 PCBs for EPE projects. Plus EPE project software © Wimborne Publishing Ltd 2004. Copyright in all ELECTRONICS MANUALS 512 drawings, photographs and articles published in Essential CD-ROM reference works for hobbyists, students EVERYDAY PRACTICAL ELECTRONICS is fully and service engineers protected, and reproduction or imitations in whole or in part are expressly forbidden. ADVERTISERS INDEX 516 Our August 2004 issue will be published on A Thursday, 8 July 2004. See page 439 for details Readers Services Editorial and Advertisement Departments 447 Everyday Practical Electronics, July 2004 437 Visit our website THE ORIGINAL SURPLUS WONDERLAND! Surplus always www.distel.co.uk THIS MONTH'S SELECTION FROM OUR VAST EVER CHANGING STOCKS wanted for cash! GIANT 10” 7-SEGMENT DISPLAYS IC's -TRANSISTORS - DIODES 19" RACK CABINETS A bulk purchase enables us to bring to you these OBSOLETE – SHORT SUPPLY – BULK Europe’s Largest Stocks of GIANT 7-segment digital displays at a now affordable Europe’s Largest Stocks price!! The 10” character size gives exceptional read- 10,000,000 items EX STOCK Save of qualityquality rack rack cabinets, cabinets, ability at long distances and enables a host of applica- For MAJOR SAVINGS enclosuresenclosures and accessories. and tions including, score boards, digital clocks, counters, CALL or see web site www.distel.co.uk £££’s event timers etc. As the units are a simple electro- Over 1000accessories Racks from stock mechanical device and operate from 12V DC, simple COMPUTER MONITOR SPECIALS switching via switches, relays, PIC or PC may be used to control single or multiple digits. Units feature integral Legacy products This month’s special BIG £ ‘Zero Power’ memory which greatly simplifies desgn. SAVER For an excellent DIY practical article, see the May issue of ‘Everyday High spec genuine multysync. 33 / 42 / 47 U - High Quality Practical Electronics’ magazine. Ideal School / College construction proj- CGA, EGA, VGA, SVGA ect. Supplied in good RFE condition, complete with data sheet. Mitsubishi FA3415ETKL 14” SVGA Multisync colour monitor with fine 0.28 All steel Rack Cabinets Less than 30% Only £29.95(B) or 4 / £99.00(D) dot pitch tube and resolution of 1024 x 768. A variety of Made by Eurocraft Enclosures Ltd to the highest possible inputs allows connection to a host of computers including of makers price Order RW44 Order PH26 spec, rack features all steel construction with IBM PC's in CGA, EGA, VGA & SVGA modes, BBC, removable side, front and back doors. Front and COMMODORE (including Amiga 1200), back doors are hinged for easy access and all THE AMAZING TELEBOX ARCHIMEDES and APPLE. Many features: Etched lockable with five secure 5 lever barrel locks. faceplate, text switching and LOW RADIATION MPR The front door is constructed of double walled TV SOUND & specification. Fully guaranteed, in EXCELLENT little steel with a ‘designer style’ smoked acrylic front used condition. Tilt & Swivel Base £4.75 panel to enable status indicators to be seen VIDEO TUNER VGA cable for IBM PC included. Order as through the panel, yet remain unobtrusive. CABLE COMPATIBLE * Only £129 (E) CG73 Internally the rack features fully slotted reinforced External cables for other types of computers available - CALL vertical fixing members to take the heaviest of Converts your colour monitor into a QUALITY COLOUR TV!! 19” rack equipment. The two movable vertical fixing struts (extras available) are pre punched for The TELEBOX is an attractive fully cased mains powered unit, containing all Generic LOW COST SVGA Monitors standard ‘cage nuts’. A mains distribution electronics ready to plug into a host of video monitors or AV equipment which We choose the make, which includes Compaq, panel internally mounted to the bottom rear, pro- are fitted with a composite video or SCART input. The composite video output Mitsubishi, IBM, etc. Supplied ready to run with all vides 8 x IEC 3 pin Euro sockets and 1 x 13 amp 3 will also plug directly into most video recorders, allowing reception of TV chan- cables, Standard RTB 90 day guarantee. pin switched utility socket. Overall ventilation is pro- nels not normally receivable on most television receivers* (TELEBOX vided by fully louvered back door and double skinned top section with MB). Push button controls on the front panel allow reception of 8 fully tuneable 14” 15” 17” top and side louvres. The top panel may be removed for fitting of 'off air' UHF colour television channels. TELEBOX MB covers virtually all tele- integral fans to the sub plate etc. Other features include: fitted cas- vision frequencies VHF and UHF including the HYPERBAND as used by £59.00 £69.00 £79.00 tors and floor levelers, prepunched utility panel at lower rear for cable most cable TV operators. Ideal for desktop computer video systems & / connector access etc. Supplied in excellent, slightly used condi- PIP (picture in picture) setups. For complete compatibility – even for monitors Supplied in good used condition. Shipping code (D) tion with keys. Colour Royal blue. some grey available – CALL – Can without sound – an integral 4 watt audio amplifier and low level Hi Fi audio out- be supplied in many other configurations. put are provided as standard. Brand new – fully guaranteed. VIDEO MONITORS TELEBOX ST for composite video input type monitors £36.95 TELEBOX STL as ST but fitted with integral speaker £39.50 PHILIPS HCS35 (same style as CM8833) attractively styled 14” 33U 42U 47U TELEBOX MB Multiband VHF/UHF/Cable/Hyperband tuner £69.95 colour monitor with both RGB and standard composite 15.625 Order as BC44 Order as DT20 Order as RV36 For overseas PAL versions state 5.5 or 6 mHz sound specification. Khz video inputs via SCART socket and separate phono jacks. External dimensions External dimensions External dimensions *For cable / hyperband signal reception Telebox MB should be con- Integral audio power amp and speaker for all audio visual uses.