Use server power supply independently

[salmanmahmood]

Hi all,

I have two server power supplies that I want to use independently as power supplies (for purposes other than server power eg a 12V source for charging batteries). The models are HP-R650FF3 by HIPRO and DPS 600-SB A by Delta Electronics. Kindly help me out.


Thanks in advance,
Regards,
Salman

 

[lw1ecp]

A 12V output is not adequate for charging "12V" batteries, you need 15V as a bare minimum, plus a series resistor to limit current. Or do the same as a conventional car voltage regulator: apply a constant voltage of, say, 14V, and well defined. In order to be able to use your PC PSUs you should:
- Open the case and see how to raise the voltage. If it has no potentiometer you will have to study what resistor is to be changed.
- On top of that, most PC PSUs sense only the +5V output. If you place a load only on the +12V, it may decrease too much, you have to connect a dummy load on the +5V also.

 

[salmanmahmood]

Hi,

I need to use these power supplies as voltage sources. Can you tell me how to do that?

Regards
Salman

 

[lw1ecp]

The steps would be more or less:
- Start the ATX PSU. You may already know this: connect the green cable to any black one.
- Measure the actual "+12V" voltage, under the intended load. If not enough (most probably), you'll have to adjust it.
- 99.9% PC PSUs don't have adjustment, you will have to patiently dig into the circuit to determine the feedback loop. It may sense just the +5, or a mix of +5 and +12. If you load just the +12, the +5 may rise to 6V or more and trip an overvoltage protection. There are many sites on how to modify PC PSUs, some with minimum changes, some may even rewind the transformer. Do a search with e.g.:
how to modify an atx power supply 13.8V
One of the results was:
https://elektronikbasteln.pl7.de/converting-computer-power-supplies-to-stabilized-138-v-dc-20-a.html