Things I've Built
4-channel "programmable" constant current source
Based on LM317 constant current circuit and the use of bcd switches to switch current setting resistance. Idea from a circuit in EDT magazine. For controlling hi power RGBW leds for microscopes.
Resistance decade box
Low cost 10 way thumb wheel switches, 3 W resistor assortment, and 3-way binding posts from freecycler contributed to a wide range resistance decade box.
0-24 V DC 25 Watt variable power supply
A buck converter module from eBay with built in digital meters for current and voltage got packaged in a nice case. A cheap and truly useful PSU.
0-1500 V 0-6 mA DC regulated power supply
A lucky find at the Cupertino flea market of a high voltage module got repaired and packaged into a nice little high voltage power supply with digital readouts of the voltage and current.
Electronics laboratory / breadboard
Took a largish solder less breadboard and added a slew of accessories like meters potentiometers, switches, fixed and variable power supply. All in one handy little "box".
ATX Power Supply conversion
This was the first or second ever clear description of converting an ATX power supply. That inspired a lot of folks to take it on. The final version ended up in a really professional looking case with an ammeter in the zero volt line.
Lutetium
Arch Reactor
Adam Fabio
ziggurat29
Samuel A. Falvo II
Malte Ahlers
zvodd
Andrew Zaborowski
Greg Kennedy
vwphan
Forbin
ken.do
ronald
Bruce Land
Daniel Young
RoGeorge
Stefan Mitic