Using A PC Power Supply

[BCR751]

I just removed the power  supply from an old computer.   Are there some connections that have to be made in the myriad of wires coming  out of it to get any outputs?  I'm measuring zero volts on all wires.

Doug

[wcfn100]

I just removed the power  supply from an old computer.   Are there some connections that have to be made in the myriad of wires coming  out of it to get any outputs?  I'm measuring zero volts on all wires.

Doug

Did you turn it on. 

Jason

[railnerd]

I just removed the power  supply from an old computer.   Are there some connections that have to be made in the myriad of wires coming  out of it to get any outputs?  I'm measuring zero volts on all wires.

Doug

ATX power supplies often need to see a small load corresponding to power button circuit in order to power up.

  http://www.instructables.com/id/How-to-power-up-an-ATX-Power-Supply-without-a-PC/

-Dave

[John]

http://home.cogeco.ca/~rpaisley4/ATpsu.html

[BCR751]

Did you turn it on. 

Jason

You know, I just knew someone was going to ask me that 

Yes, I turned it on.  Do one, or all, of the Mole plugs have to be plugged in before irwinx37@yahoo.com will work?

Doug

[BCR751]

Did you turn it on. 

Jason

I just knew someone was going to ask me that 

Yes, I turned it on.   Do some, or all, of the Molex plugs have to be plugged in before it will work?

Doug

[peteski]

I'm not a fan of using those power supplies for model RR uses.  They aren't really designed for that.  They are designed for all the outputs to have loads on them at all times.  They also supply more current than usually needed for model RR uses. While they are short-circuit protected, if the short is not a dead short then they can supply enough current to heat up the short area or even the wiring between the short and the supply (to the point of starting a fire).

Is yours AT or ATX supply?  John's link is for AT supplies (the older ones from the 80s and early 90s.) ATX (the newer supplies) are different. They also have 3V outputs.  Also they have a lead used for turning them on or off remotely.

[BCR751]

Well, I hadn't planned on using it for anything in particular, just thought it would be a shame to toss it. It could come in handy for fiddling on the bench.   It has s whole bunch of outputs, +/- 3v, +/- 5v, +/-12v all at various current ratings. It does have a green wire and where it's attached to the circuit board it says "PC ON".  Maybe this has to be shorted to ground to turn the supply on ?

Doug

[RBrodzinsky]

Check out this link for very good details. http://web2.murraystate.edu/andy.batts/ps/powersupply.htm

I have used one to provide all my auxiliary power (lighting, animation, power to accessories, etc). I do not use it for any power that will feed to the track, for exactly the reasons peteski mentions.

[peteski]

Ah, so this is ATX supply.
This should be helpful: https://makezine.com/projects/computer-power-supply-to-bench-power-supply-adapter/

[bobthebear]

I've used one for all my lighting, relays and detectors for many years without trouble. Just add a switch between the green wire and any black wire to turn it off/on and it will work.

Cheers, Bob.

[lyled1117]

Most PC supplies need two of the pins shorted together to operate. This short is provided on the motherboard of a computer to complete a circuit that turns them on. The following link shows the two pins involved

http://www.wikihow.com/Check-a-Power-Supply

Lyle

[conrail98]

One of the layout pages on Facebook I follow, the gentleman bought two of these and is using them for powering switch machines, control panel switches and LEDs, and I even think the UP5s (I'm pretty sure his staging yard construction video says that). Here's a link to his video:

Remember, there are many ways to do this and just looking at a quick search shows a lot of different ways to ensure the capacitor is drained before you work on it, set it up for powering up and down, getting the wires out to where they need to go, etc.

Phil

[John]

One of the layout pages on Facebook I follow, the gentleman bought two of these and is using them for powering switch machines, control panel switches and LEDs, and I even think the UP5s (I'm pretty sure his staging yard construction video says that). Here's a link to his video:

Remember, there are many ways to do this and just looking at a quick search shows a lot of different ways to ensure the capacitor is drained before you work on it, set it up for powering up and down, getting the wires out to where they need to go, etc.

Phil

Love the 2U rack .. nice setup .. but overkill IMHO

[BCR751]

Thanks for all of the inputs, guys.  I'll go ahead and try grounding that green wire and, if it works, I'll have a little low-voltage supply I just know I will be able to find a use for.

Doug