Connecting DUAL power supplies to a single computer/motherboard

[rwatki]

I have been looking for a way to use 2 power supplies for a single computer/motherboard. The goal is fault-tolerance, similar to that seen in Server class hardware.
There are many "adapters" out there, but those only power accessories. What I am looking for is a way to have the entire computer including the motherboard powered from 2 supplies, so that the system will continue to run regardless of which power supply is off, as long as a single power supply is still on.

 

[thor220]

This topic has been discussed many times before and while it can be done, it requires significant effort. Questions like "How do the power supplies distribute load?" and "How is voltage regulated between the two?" come into play.

You can find article on how to do it but unless you are experienced at modifying electronic, don't do it. Working on Power Supplies is very dangerous (charged capacitors) and can lead to death.

If you need more power, put a larger power supply.

 

[rwatki]

My specific goal is to be able to draw power from 2 different UPS systems. Both are rather old, and I have had to take the system offline before to replace the batteries in the UPS. I would like to be able to keep the system running, even if one of the UPS's goes offline.
I have some experience with electronics, but not as a designer. I would feel comfortable wiring up a solution, if I had one which would work. I searched through 2 pages of google, but everyone keeps talking about the simple situation of powering a second PSU when the first PSU starts, and using the second PSU for accessories, not the motherboard itself.

 

[hang-the-9]

Many server systems have redundant power supplies if you really need that kind of reliability with uptime. I don't know of any way of wiring a system up with dual power supplies on your own for fail-over use.

There are some devices listed in this thread, but they cost about the price of a full PC. http://community.spiceworks.com/topic/193207-dual-power-for-single-cord-gear-is-there-an-smb-power-transfer-switch

 

[thor220]

My specific goal is to be able to draw power from 2 different UPS systems. Both are rather old, and I have had to take the system offline before to replace the batteries in the UPS. I would like to be able to keep the system running, even if one of the UPS's goes offline.
I have some experience with electronics, but not as a designer. I would feel comfortable wiring up a solution, if I had one which would work. I searched through 2 pages of google, but everyone keeps talking about the simple situation of powering a second PSU when the first PSU starts, and using the second PSU for accessories, not the motherboard itself.

The most I've ever see is people powering the graphics card, optical drive, and some fans with a 2nd PSU. I'm sure somewhere, someone has a two PSUs rigged together, just can't seem to find it anywhere on the internet. The reply here is pretty good on the issues

http://superuser.com/questions/681919/using-multiple-power-supplies-in-one-pc