Two PSUs in a Case is it possible?

BigDonut · Post by **BigDonut** » Fri Jan 07, 2005 12:05 pm

I'm currently sourcing parts for a new system and was struck with the idea of putting two PSUs in a system

From what I've read efficency is important in keeping the noise down.
Some of the 250W supplies are close to 95% efficent (I read that somewhere on here but can't find the link).

In theory would 2 very efficent PSUs be benificial. Not quite sure how you would rig it up but I'm sure someone on here could come up with an idea.

Also would it work connecting your MB and HDD drives to one and GFX and other drives to the other PSU. I don't see why not.

Personally I won't be trying this road but wondered if it had been done/ could be done

greeef · Post by **greeef** » Sat Jan 08, 2005 10:49 am

Yes it's pretty easy.

All you need to do is hook up a 12V relay that'll close two pins on the 20 pin atx connector that isn't plugged into a motherboard.
I can't remember which pins but google knows.

BigDonut · Post by **BigDonut** » Sat Jan 08, 2005 11:24 am

greeef wrote:Yes it's pretty easy.

All you need to do is hook up a 12V relay that'll close two pins on the 20 pin atx connector that isn't plugged into a motherboard.
I can't remember which pins but google knows.

so a power supply won't provie power to other components unless its plugged in to the motherboard?
I didn't know that, thanks

Qwertyiopisme · Post by **Qwertyiopisme** » Sat Jan 08, 2005 12:21 pm

BigDonut wrote:
greeef wrote:Yes it's pretty easy.

All you need to do is hook up a 12V relay that'll close two pins on the 20 pin atx connector that isn't plugged into a motherboard.
I can't remember which pins but google knows.
so a power supply won't provie power to other components unless its plugged in to the motherboard?
I didn't know that, thanks

Well seeing as how the power switch is connected to the motherboard it would be quite logical that the PSU gets a signal from the mobo to turn on/off :p.

Oh and it's green that should be shorted to ground (black).

Post by **MikeC** » Sat Jan 08, 2005 1:24 pm

Coolermaster Stacker has space for 2 PSUs -- one on top, one on the bottom:

wim · Post by **wim** » Sat Jan 08, 2005 5:05 pm

12V relay..interesting greeef *rubs chin*
do you have to give the PSU a common ground?

what 250W supplies are ~95% efficient? i thought it was only DC/DC conversion which could reach that sort of efficiency

BigDonut · Post by **BigDonut** » Sat Jan 08, 2005 5:49 pm

Qwertyiopisme wrote: Well seeing as how the power switch is connected to the motherboard it would be quite logical that the PSU gets a signal from the mobo to turn on/off :p.

yes that is quite logical, I was looking for something more complicated

what 250W supplies are ~95% efficient? i thought it was only DC/DC conversion which could reach that sort of efficiency

I may well have confused more than one thing I've read and thought that DC-DC supplies being discussed were standard PSUs.

Is it still not the case that some of the small psus particularly those for shuttle tpe systems are highly efficent (even if not 95%)?

The stacker case looks nice mike but I'm not looking any more cause I'll just get frustrated that its out of my budget

greeef · Post by **greeef** » Sun Jan 09, 2005 8:42 pm

wim wrote:12V relay..interesting greeef *rubs chin*
do you have to give the PSU a common ground?

what 250W supplies are ~95% efficient? i thought it was only DC/DC conversion which could reach that sort of efficiency

Well there may be a slight delay in the second psu powering up, but i cant see any issues in theory...havent tried it myself though i've powered up many a psu with the wire trick.

And on the common ground point, if they're both plugged into the mains and screwed to the case, cant see it getting any more common...

griff

wim · Post by **wim** » Mon Jan 10, 2005 5:45 pm

ah yes.. i forgot that normal people generally have their PSU(s) screwed into some sort of case

whoops

mathias · Post by **mathias** » Mon Jan 10, 2005 5:58 pm

wim wrote:ah yes.. i forgot that normal people generally have their PSU(s) screwed into some sort of case whoops

They do? Oh. Weirdos.

Tyrdium · Post by **Tyrdium** » Mon Jan 10, 2005 7:47 pm

Bah, I just use duct tape.