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
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.
Step 2: Preparing You Project Box
Step 3: Wiring the Power Supply Up
All the solder connections should utilize heat shrink in the event a connection comes lose and to ensure you get no shorts in the system.
The schematic would be as follows. I did not utilize the fuses in line. The resistors are required for the LEDs and I bought a round switch. Wiring for all other components is correct. I used 2 5 Watt resistors in series in place of the one 10 Watt. Some supplies require an initial load in order to turn on. Before turning your supply on you should CHECK ALL YOUR CONNECTIONS TO ENSURE THE SYSTEM WAS WIRED CORRECTLY.
The red led will turn on when the ATX supply is plugged in. The green led will signify the switch is turned on, supplying power to the rails. Everything worked great and I was very pleased with how everything turned out.
I have a few references on my blog site that have some additional detail.