Computer Power Supply Probs - Help!!! - RC Groups
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Feb 15, 2003, 06:15 PM
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Computer Power Supply Probs - Help!!!

Can anyone out there help me!!!?

I am trying to set up a computer power supply as a 12v source for my battery chargers and I'm having some problems...

The unit I have is an Enermax EG231P-V. It is an ATX-style 230W switching power supply rated at 20A/5v and 10A/12v.

I found some info on this forum and have jumpered the green/black motherboard wires and the fan kicks on strong, then seems to slow down, but doesn't stop. Shouldn't the fan stay on strong?

I also jumpered the gray/red wires, but it didn't seem to have any additional effect.

Without hooking a resistor to the 5v side, I'm getting 12.0 on the 12v side. If I attach my Dymond Turbo Supercharger to the 12v, the PS shuts down. If I attach the DTS before turning the PS on, then the PS will stay on. When I tried to charge a battery I got an input voltage error on the DTS.

Putting a resistor on the 5v side brought the voltage on the 12v side up a little. When I tried to charge a battery with the DTS, I was able to draw a little more current, but got the error again when I tried to pull about 4A. Shouldn't I be able to draw more than 4A out of a 10A supply?

Has anyone else out there had a similar problem that could perhaps steer me in the correct direction???

Chuck in Indy
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Feb 16, 2003, 12:55 AM
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Marked's Avatar
I am not familar with these power supplies......I just would stick to the old AT power supply....there are a lot around and they are mostly free,and easy to convert.I did pay a dollar for 1 at a yard sale.....I was in a pinch on vacation and needed one for my 110D......the older(286-386) machines had good current on the 12V side.Mark
Feb 16, 2003, 02:37 AM
Registered User
The power supply requires the 5V supply to have a load of at least 10 A for the 12V supply to work. It has to do with there being to large of a load inbalance between the 5V and 12V supply. Under normal conditions for the power supply, the 5V supply has a larger load then the 12V supply. At least you will have a nice heater to keep your room warm.
Feb 16, 2003, 08:33 AM
Registered User
Thanks for the info on the 5v load...!

To generate that much load, I will need two 1ohm/25watt resistors wired in parallel. PS will see 0.5ohm and draw 10A. Resistors will need to absorb 50watts total, which will max them out. I'm sure it will keep things nice and warm!

Now all I have to do is find the resistors...

Chuck in Indy
Feb 16, 2003, 11:11 PM
Registered User
Just another option to using the resistors. I went to the local auto parts store and bought a 1157 light bulb and mounted it in an amber parking light housing. wire 5v to both elements on the bulb. this draws enough to make the ps put out about 12.1V. it makes a nice indicator light to tell you when the ps is turned on too.