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Proposed Format for KitStop 4cm Ads Silicon Chip Magazine February 2012 Advertising Index Altronics...................................... 82-85 Amateur Scientist CD..................... 102 Australian Valve Audio................... 103 Clarke & Severn Electronics............ 91 Dyne Industries.................................... Emona Instruments............................ 7 Geoff Coppa.................................. 103 Select to print full color. Grantronics.................................... 103 Harbuch Electronics......................... 12 DOWNLOAD OUR CATALOG at Hare & Forbes.............................. OBC www.iinet.net.au/~worcom HK Wentworth.................................. 10 WORLDWIDE ELECTRONIC COMPONENTS PO Box 631, Hillarys, WA 6923 Ph: (08) 9307 7305 Fax: (08) 9307 7309 Email: worcom<at>iinet.net.au Instant PCBs.................................. 103 Jaycar ................................. IFC,49-56 Keith Rippon.................................. 103 Kitstop............................................ 104 FK708 AM Radio Kit Circuit Ideas Wanted We pay up to $60 for contributions to Circuit Notebook, or you could win aan LCR meter. Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. Ask SILICON CHIP . . . continued from p101 controller on your layout you really need to install block switching between the inner and outer loops, with double-pole changeover relays. You cannot use any system where the two controller outputs are effectively connected in parallel, even if it occurs only briefly. Modifying the Sunset Switch In June 2003 you published a design for a Sunset Switch. This includes a timer which I don’t need and which adds to the cost and complexity of the circuit. Has there been a design that has only the sunlight sensing with hysteresis? I need to turn some lights on overnight only. Perhaps the circuit could be adapted by taking the output at pin 7 of IC1 and running the relay through Q1 from there? Then there would be 104  Silicon Chip For this kit and hundreds more like it, shop on-line at: Ideal classroom project or just for fun. Simple construction Includes amplifier and speaker Shelf and pocket cases available www.kitstop.com.au Value!!! $15.27 inc GST electronics - the fun starts here Plus $6.45 P & P February 2012 no need for Q2, IC2, IC3 etc? (J. B., via email). • The Sunset Switch could be modified to remove the time-out as you suggest. There are several ways to do this. (1) One option is to remove IC2 and IC3, the DIP switch, S2 and S3, diodes D6-D11, transistor Q2 and the associated resistors and capacitors for the power-on reset, dawn light reset and for oscillator IC3. Pin 7 of IC1b then connects to the base of Q1 via the 3.9kΩ resistor. That way, the relay would be closed whenever the sensor is in darkness. (2) To preserve the manual on and off switching, only remove IC3, the DIP switch and diodes D6-D9 plus the associated resistors and capacitors for IC3 at pins 9-11. (3) Alternatively, the project can be built as shown and the DIP switches all left open so that there is no time-out. Finally, the Solar-Powered Lighting Controller published in the May 2010 issue of SILICON CHIP can also be used SC as a sunset switch. LED Sales...................................... 103 LHP.NET.AU................................... IBC Measurement Innovation................. 91 Microbee Technology..................... 104 Microchip Technology....................... 41 Microzed Computers........................ 91 Mikroelectronika............................... 11 Mouser Electronics............................ 5 Ocean Controls.................................. 3 Quest Electronics........................... 103 RKT Auctioneers.............................. 89 RF Modules................................... 104 Sesame Electronics....................... 103 Silicon Chip Binders............. 30,46,103 Silicon Chip Bookshop................ 92-93 Silicon Chip Order Form.................. 98 Silicon Chip PCBs................... 100,103 Silicon Chip Subscriptions............... 96 Siomar Battery Engineering........ 9,103 Splat Controls................................ 103 Truscotts Electronic World............. 103 Wiltronics......................................... 13 Wireless Design............................... 91 Worldwide Elect. Components....... 104 siliconchip.com.au