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Re: [LUG] (Non-Linux Topic) Daisy chaining power-supplies?

 

On 8/18/06, Grant Sewell <dcglug@xxxxxxxxxxxx> wrote:
.  Is it possible to daisy-chain two PSUs so I have the extra
> power I need?  I know that the ATX PSUs don't work unless connected to a
> motherboard and the power-switch was pressed... I'm guessing a couple of
> pins on the mobo connector would need shorting?

Hi Grant,

By Dazy chain I assume you mean connect in parallel. DO NOT DO THIS,
if you connect two power supplies together they can fight as they both
are attempting to get a given voltage, if that voltage is not
100.000000% the same the regulation circuits will both attempt to
compensate and you will just drive large amounts of current from one
PSU to the other. It is possible to connect *some* times of PSUs in
parallel but they are designed specificy for this (and are not PC
power supplies)

It would be possible to use seperate PSU's to power different devices
as long as you have A COMMON GROUND. Ie the black wires (of the two
PSUs) should be joined together in ONE place. It is necessary to join
one pin of the 2nd PSU to ground as well (PS ON pin 14) This is what
the MB does to the PSU when you press the button to enable the 12V and
switched 5V supplies. You could also join the two pin 14( green wires)
together so that the MB switched both PSUs on together. But i would
not attempt this kind of hacking unless you are confident in
electronics and have approprate test equipment.


Best regards

-- 
Robin Cornelius
http://www.byteme.org.uk

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