Need 24VDC + 10-15A..Have 2 PC PSUs...

[bob4432]

working on a project and need ~24VDC w/ some decent A. have a couple older 300W PSUs siting around - anybody know of a tutorial on connecting them in series to get my 24VDC?

thanks in advance,
bob

 

[Yellowbeard]

I don't think 2 PSUs in series will work like 2 batteries in series. Meanwell makes a 24v PSU, I think they make it for TEC coolers.

 

[Mark R]

PC PSUs have ground references outputs. That means the 0V line is connected to the chassis ground.

You can't simply connect 0V on one PSU to +12V on the other, because it would be the same as connecting 12V on one PSU to 0V on the same PSU - since both PSUs share the same ground.

While, theoretically, you could disconnect mains ground from one PSU and insulate it so that any metal parts on it do not come in contact with the other PSU, this is a dangerous solution - indeed, it may not even work, as some PSUs don't regulate correctly without a good ground.

It essentially can't be done safely and simply.

 

[bob4432]

thanks for the info. will look for a standalone unit - maybe i can get away w/ around 8-10A...

again, thanks for all the info

 

[Rubycon]

You can do it with a single PSU providing it has enough spare 12V amps. DC-DC converters are efficient but you will have to make up for conversion losses.

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[Zepper]

check http://www.halted.com - they usually have some unusual PSUs as does www.bgmicro.com - but you have to watch BG as they once sold me a stand-alone PSU that was over 20 years old - not worth the shipping on it as all the caps would have to be changed out for me to be comfortable using it - it was "new" AFAtheywereC, had never been used. You don't want to buy a PSU that is more than a couple of years past date of manufacture if you want some good life out of it.

.bh.