Bitcoin Forum

Other => CPU/GPU Bitcoin mining hardware => Topic started by: stryker on September 05, 2011, 01:42:58 PM



Title: PSU can I bridge the DC rails to put the WATTS where I need them?
Post by: stryker on September 05, 2011, 01:42:58 PM
Just toasted a 850 watt psu.

I realiase now that the psu had two 38 amp 12v rails providing 336 watts each.  As it happens one rail had one gpu on it while the other had 2 on it and was thus over-loaded.

Now I have the replacement on order I have this question.

Is there anything stopping me from "bridging" the two rails? I'd do it by splicing the wires together outside the PSU.  I'm fairly familiar with DC and can't immediatly see an issue with this but thought I ought to ask.

Also more to the point, if I can do that, then whats to stop me doing it across several PSUs ?

Cheers


Title: Re: PSU can I bridge the DC rails to put the WATTS where I need them?
Post by: stryker on September 05, 2011, 01:51:10 PM
doh of course i cant, i imagine id have one rail driving the other an kaboom as its too much to expect the voltages to match exactly?


Title: Re: PSU can I bridge the DC rails to put the WATTS where I need them?
Post by: abracadabra on September 05, 2011, 02:28:48 PM
Just toasted a 850 watt psu.

I realiase now that the psu had two 38 amp 12v rails providing 336 watts each.  As it happens one rail had one gpu on it while the other had 2 on it and was thus over-loaded.

Now I have the replacement on order I have this question.

Is there anything stopping me from "bridging" the two rails? I'd do it by splicing the wires together outside the PSU.  I'm fairly familiar with DC and can't immediatly see an issue with this but thought I ought to ask.

Also more to the point, if I can do that, then whats to stop me doing it across several PSUs ?

Cheers


Yes you can.  Internally the PSU most likely has a single 12V output and the only thing separating the output rails is a current limiting resistor.


Title: Re: PSU can I bridge the DC rails to put the WATTS where I need them?
Post by: stryker on September 05, 2011, 02:56:03 PM
hmm interesting thought.... I may just try that just to find out..... I have 3 GPUs and TBF on the old PSU if I had joined the rails and it had worked then I think it would still be ok to this day.


Title: Re: PSU can I bridge the DC rails to put the WATTS where I need them?
Post by: stryker on September 06, 2011, 07:11:52 PM
I see, my God I used to know that because I played with PV about 10 years ago :-)

Thanks for the refresher