I bought a few strands of cheap LED Xmas lights this year. They include a circuit box with several settings to make the lights flash in different patterns. The circuit box resets itself (to a new annoying setting) each time the lights are unplugged or when it shorts out in the rain, and I also suspect the box is the product's "built-in expectancy" (since otherwise LEDs might last too long to be profitable. Can I bypass the box? [more inside]
posted by Shane on Dec 21, 2011 - 8 answers

What are some reasonably complex and conceptually interesting electronics projects that I can make for my class? [more inside]
posted by cognitio on Mar 14, 2011 - 5 answers

I'd like to use a single 5mm UV LED (3.4V_f, 20-25mA) to charge a daub of glow-in-the-dark paint. It only needs to be lit around 1 minute of every 10 (or 6 seconds of every 60), and only when the (room) lights are out. What battery/circuit would be most economical to operate, and require the least-frequent battery changes? [more inside]
posted by jjjjjjjijjjjjjj on Jan 18, 2011 - 6 answers

I have a lot of (old) ICs Integrated Circuits. (Also, crazy piles of capacitors and resistors, etc. but let us concentrate on the ICs.) Is there a website where an average citizen with these items can sell them to buyers? I fear they would just get lost buried or unseen on "ebay", even moreso on "craigslist". SeekIC.com seems like the kind of site I am after, but I would like to sell to buyers in the USA. [more inside]
posted by shipbreaker on Jan 2, 2011 - 8 answers

What is the Thévenin equivalent of this circuit? [more inside]
posted by PuGZ on Jun 14, 2010 - 6 answers

I have a medium-sized run of printed circuit boards that'd be most cost-effective for me to silkscreen/photo-etch at home. I'm pretty sure I got that part covered... lots of tutorials available [1, 2, 3, etc]. It'd be a shame, though, to build this setup and then not use it again, so I'm wondering where are some great repositories for (all types of) PCB layouts? Added difficulty: Would like reasonable descriptions of "what they do" and how the boards are likely to be employed. [more inside]
posted by jjjjjjjijjjjjjj on Dec 30, 2008 - 7 answers

I'm making a timer for skateboard racing and need some help. Does anyone have some advice on wiring simple circuits to lend? [more inside]
posted by infomaniac on Jul 6, 2007 - 8 answers

I need suggestions for a good book that covers digital circuit design (specifically practical design using MSI/LSI TTL, PLD's, CMOS, FPGA, etc. [more inside]
posted by beammeup4 on Sep 21, 2006 - 2 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