I have a few 12 V motors and other sensors/electronics that require anywhere from 3-12 Volts. I usually use a battery pack but did not want to continue to go through batteries. For prototyping, I decided to convert an old ATX power supply into table top power supply. This generally will allow you to have terminals for +12V, +5V, +3.3V and potentially a -5V and -12V. These voltages are pretty common for anyone who works with micro-controllers and sensors.
This project uses:
-x2 mounted LEDs
-ATX Power supply
-Various heat shrink sizes
-x2 5 watt resistors
-x2 330 ohm resistors
Step 1: Preparing an Old ATX Power Supply
There are a bunch of references for building them. First thing I did was find a supply laying around I could use. You can reference the diagram below for the color coding of the ATX supplies.
ATX supplies can put out a good amount of current. If the maximum amount of current were to be pulled I recommend using all the wires at a given voltage to withstand max current draw. It may be 12 ground wires and 4 +3.3V wires etc...
**WARNING!!!! BEFORE CUTTING WIRES, USE A MULTIMETER TO CHECK THE CAPACITORS TO ENSURE THEY ARE NOT STORING ANY ENERGY. IT WOULD ALSO BE A RECOMMENDATION TO LET THE SUPPLY SIT FOR SEVERAL DAYS FOR ANY CHARGE TO DISSIPATE"
Remove the cover and cut the adapters off of the wires coming from the supply. You should be left with a large amount of wires that will need to be stripped.