linking 2 PSUs
 

i am trying to link 2 power supplies to power my computer
one is powering the MB, GPU, and the OS HD
the other is powering 8 HDs
i need both PSUs to turn on at the same time

i know i've seen this somewhere on the forum but can't find it

thanks

jman

Re: linking 2 PSUs
 

Strangely, we don't have an article on it here. (multiple ATs, load sharing, yes, but not two ATX PSUs).

What you want to do is tap into the PWR_ON line provided by the motherboard; it commands the PSU to turn on. You won't be using the PWR_GOOD line from the second PSU (the one you'll use for the HDDs).

Can you get the pinout of the mobo power connector?

Re: linking 2 PSUs
 

will this do?

Re: linking 2 PSUs
 

or is this what you were looking for?

Re: linking 2 PSUs
 

The second one. See the line named "PSON#"? That's the signal line through which the mobo commands the PSUs to turn on.

;)

Re: linking 2 PSUs
 

there are 2 articles on the website about this:
http://www.procooling.com/index.php?...ticles&disp=56

http://www.procooling.com/index.php?...ticles&disp=52

Re: linking 2 PSUs
 

thanks, Joe

Re: linking 2 PSUs
 

so something weird happened.
after linking the two PWR_ON lines, the 2nd PSU turns on right away
but when i power up the pc it turns off and the main one turns on

the MB is a epox 8KDA3I, main PSU is an Antec trupower 380 and 2nd is an Ultra 500 (it was free after rebate)

the weird thing about this MB is to get it to boot, i always have had to remove power from the the PSU, depress the power switch, and then simultaneously apply power to the PSU and release the power switch
otherwise, it would do nothing

on a side note: should i ground the PSUs together?

Re: linking 2 PSUs
 

bump (10 char)

Re: linking 2 PSUs
 

Sounds like you already had a fault to start with.

Maybe you could swap the PSUs to see if the fault is with the PSU, or the mobo?

The PSUs are probably already grounded, if you mounted both in the case.

Re: linking 2 PSUs
 

i have tried several PSUs (singlely)
all have the same issue

Re: linking 2 PSUs
 

That's a mobo problem.

Once the Power_on signal is generated by the mobo (to the PSU), it waits for a Power_good signal from the PSU (indicating that all voltage rails are in spec), then turns everything on.

I have no idea how you'd go about fixing that. Someone else?

Re: linking 2 PSUs
 

take a 12v automotive relay.

On your 2nd PSU connect pin 14 to connector 87 on the relay...and pin 15 to 30 (on relay)..

On your main PSU connect any 12v to connector 86....and 85 to any ground wire on your main PSU.

Good luck