On the white 4-prong plug that would go to a disk drive, the red wire is +5 Volts and the yellow wire is +12 Volts. The two black wires are ground and are probably connected together within the power supply. This is standard color coding for any computer power supply's disk drive wires.
Depending on the Wattage rating of the supply, the +12 Volt output can range from 5 Amps to as much as 30 or 35 Amps, and the +5 Volt can be equivalent or higher Amperage.
Matching connectors can be purchased from several on-line sources or maybe even a local computer repair shop, so there's no need to ever open up the case.
I use computer power supplies all the time for building and signal lights, switch motors, etc.; just about any accessory for which you need power.
When I run power bus wiring around a layout, I always provide for three power sources: DCC track power; +12 Volts DC, and +5 Volts DC. I can then tap off wherever I need by putting a terminal strip in the lines.
JLK I was wandering if a computer power supply could be used to power things on my layout. I have two unused ones. Thanks in advance.
I was wandering if a computer power supply could be used to power things on my layout. I have two unused ones. Thanks in advance.
Yes they can. Since they are a switching supply thus they must have a load on them. A light bulb will do.
They have 5 volt outputs, and 12 volt outputs. In computerdom the black wire I believe is ground, and the colored wire carries the voltage. The +12v dc has all of the amperage that you will need, the -12 dc has considerably less. You will recognize the big 12volt molex plugs such as are plugged into the hard drives and cd ROMS etc.
I would NOT open it up, but then again I would not worry about 12 voltage remaining on the line.
ROAR
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Here there be cats. LIONS with CAMERAS
SOmethign I've suggested a few times - those instructions all rely on openign up and modifying the computer power supply. There are large capacitors in those that maintain quite a bit of power even after it's completely unplugged fromt he wall, so BE CAREFUL. As an alternative, you CAN get mating connectors for the ones already on the power supply, and make all the modifiications external to the supply, eliminating the need to open them up. Plus if the original power supply dies, you cna unplug your circuit and plug it into a new power supply and continue on.
--Randy
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Computer power units make great power supplies because the output voltage is regulated.
If you don't really know what you are doing, I would suggest don't try.
Below might give you some ideas though.
http://web2.murraystate.edu/andy.batts/ps/POWERSUPPLY.HTM
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
Make sure you have some kind of load on the voltages. At one time it was known the a PC supply voltage with no load might rise to a level that would damage the filter capacitor. With the newer breed of PC supplies that might not be an issue anymore.
You should have fuses in line with each feed. The 5 volt supply amps can be quite high. Many just use the 12 VDC supplies and maybe the 5 volt for digital logic power.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
I don't know what the amps are but the volts are 12 to 3 or 5.
Justin
What is the voltage and amps of the output? I have used an old powersupply, I think it was for an old printer, and it worked well for powering my light on my layout. It changed the AC to 12 Volts but I dont remember what the AMPs are right off but it is in line with the basic DC/AC powerpack that came with my Altas Trainman set