PC Power supplies, more pain then they're worth

Nodent

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I received some power supplies and got 1 of the 3 working.

1.) ComPaq PDP-100 - no idea how to hotwire it

2.) CompUSA - worked when I hot wired it, seperated all the wires and capped off unused ones. Go to turn it on and the fan jiggles for a split sec but won't power up.

3.) working so far

I just can't swallow Ray's shipping costs to get them from him.
 

David_AVD

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As for #2, you'll need a minimum load on the 5V line to make it run. Try a 10 Ohm 5W resistor.

But yes, generally using PC power supplies is not worthwhile.
 

Nodent

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I figured out Number 2

Researching online I found that I have an orange line coming from the IC labeled S+ and a black labeled S-.

The Orange S+ had to go to orange +3.3V (When I tried it to red 5V it would power on for like 2 sec then shut down)
The Black S- had to go to ground.

I did put 10ohm 10watt resister from +5v to ground for good measure.

This stuff pulls my hair out but fun at the same time. Wait I have no hair to pull. :p
 

fasteddy

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Computer power supplies are best used for computers. with lighting we have lots of varying loads and a computer power supply is not designed to have such large fluctuations in power draw.

If you have them lying around then it may be worth while giving them a go, but its not worth saving a few dollars just to buy a cheaper power supply
 

DanJ

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Eddy--just full of questions tonight.... I purchased some new ATX PSUs this year with the intent of using them with some of the smaller "distributed" controllers that drive 120 to 150 pixels or so... Would you include the ATX type PSUs in your statement above to stay away from PC PSUs? Thanks again....
 

fasteddy

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DanJ said:
Eddy--just full of questions tonight.... I purchased some new ATX PSUs this year with the intent of using them with some of the smaller "distributed" controllers that drive 120 to 150 pixels or so... Would you include the ATX type PSUs in your statement above to stay away from PC PSUs? Thanks again....
If it works then all good, many people have used these power supplies in their setups for many years, it all depends on the brand and internals of the power supply as they are not all alike. If you already have them then use them.
My statement is more about if you are going to choose between the two then you are better to choose the standard switch mode power supply rather than a computers power supply. But if you already have them then may as well give them a go.
 

DanJ

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Thanks again, Eddy. I just bought the ATX PSUs from TigerDirect this spring. They are CoolMax 500W PSUs. I followed some advice you gave others before last Christmas--kind of stayed on the lower end of the cost scale but bought an extra one in case I have a failure.
 

DanJ

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Good point Alec. Well, this year I am at least going to give the ATX PSUs a shot and see how they do. Maybe I will learn a painful lesson.....
 
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