At Fri, 01 Jul 2011 16:25:33 +0200 CentOS mailing list <centos at centos.org> wrote: > > Colin Coles wrote: > > On Friday 01 July 2011 12:05, Timothy Murphy wrote: > >> > >> Any advice or suggestions gratefully received. > > > > If you are thinking of the UPS route a caveat: I have several HP servers and > > most of them will not work on cheap UPS's as they do not produce the pure > > sine wave modern HP machines require but rather a crude stepped voltage. > > perhaps naively, I'm surprised: doesn't this mean they put crappy PSUs > in those servers? > I thought decent PSUs were expected to deal with dirty input AC? AND *I* thought *switching power supplies* (effectively) rectified the AC input and then used the DC to drive a higher frequency system to get the desired output voltages. (The higher frequency means smaller, more efficient transformers and need smaller filter caps -- all of which means a lower cost, more reliable, more efficient power supply.) Which suggests that both the input voltage and frequency are not particularly critical, so long as it does not have massive spikes/surges or consistently low voltage. > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > -- Robert Heller -- 978-544-6933 / heller at deepsoft.com Deepwoods Software -- http://www.deepsoft.com/ () ascii ribbon campaign -- against html e-mail /\ www.asciiribbon.org -- against proprietary attachments