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Unread 09-25-2002, 04:21 PM   #31
murray13
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Join Date: Sep 2002
Location: Omaha, NE USA
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Here is a link to the pdf at Texas Instruments web site:

http://www-s.ti.com/sc/ds/ucc39002.pdf

Quote:
as it is a question of running the PSU(s) cool and steady.
Well, from my observations over the years, especially with power supplys, one good unit running at 90% will almost allways outlast two cheap units running at 68%. Key word here is GOOD supply.

Also about running cool...it all boils down to the efficiencys of the P/S's. A 450W running at 90% capacity with a efficiency of 87% will put out 52.65W of heat. Two 300W running at 67.5% capacity with a efficiency of 87% will also put out 52.65W of heat. In both cases they supply 405W of power. But remember that is just the theory. In real life the two 'cheap' P/S will probably not be 87% efficient, you would have the additional fans running from the second supply, and you cut the MTBF (mean time between failure) in half by using two instead of one. By having two instead of just one your twice as likely to have a failure. I will admit though, all other things being equal, two P/S running at 2/3rds power should in theory run longer than one running at 90%.


If you decide to integrate that IC between two P/S, I'd love to help. It would be nice to document the process and post it all over the place. Providing a 'poor man's' "server" supply.

Whichever way you end up going I look forward to seeing the results.
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