I need some electronics help - why is this FET not doing what I expect it to? [more inside]
posted by backseatpilot on Nov 17, 2009 - 16 answers

What's the best way to make a Crackle Box-type circuit (where the user touches and closes the circuit with their fingers)? [more inside]
posted by itchi23 on Mar 24, 2009 - 4 answers

Where can I buy a discontinued 11C90 650 MHz prescaler? This is for reverse engineering a SR-2020 mystery receiver that a friend of mine has been working on. Any information on this will be very much appreciated. Bonus hand drawn analog circuit diagrams. [more inside]
posted by mikw on Mar 13, 2009 - 3 answers

How do I build a microphone preamp for a Macbook Pro? [more inside]
posted by knowles on Jan 25, 2009 - 6 answers

can you help me locate a circuit diagram of a gps module on internet? [more inside]
posted by raphael19 on Aug 5, 2008 - 5 answers

Electronics filter. Game show buzzer+. There are tons of simple game show buzzer layouts on the google. What I can't seem to find is an idiots guide to something that would allow you to take an input more complicated that a simple yes/no. i.e. interrupt + [string]. Any pointers?
posted by Jakey on Jun 26, 2008 - 3 answers

ElectronicsFilter: How do I drive a step-up transformer to get hundreds of volts out of an AA battery? They're only 1.5v. [more inside]
posted by spacewrench on Sep 3, 2007 - 7 answers

I have a simple Sony reel-to-reel tape deck from the 1960's that I'd like to install a speed control on. Since I have no electronics skills, can anyone here recommend an ace 'circuit bender' in the Los Angeles area? Thanks :)
posted by starscream on Mar 1, 2007 - 3 answers

Any suggestions for a small, battery-powered flashing LED setup I can use for an outdoor mock alarm? [more inside]
posted by pallen123 on Oct 21, 2006 - 5 answers

I'd like to trigger a relay that momentarily closes a switch based on the voltage of another wire. Maybe. I think. Please help me with this basic (I hope) electronics project. [more inside]
posted by odinsdream on May 14, 2006 - 6 answers

I want to learn how to make simple electronics, like LED controllers that I can hook up to a serial port. Can anyone recommend a book to get started with? [more inside] [more inside]
posted by krunk on Aug 29, 2004 - 13 answers