At Sat, 02 Jul 2011 15:42:38 +0200 CentOS mailing list <centos at centos.org> wrote: > > Jason Pyeron wrote: > > >> Could you (or anyone) suggest a cheap UPS? > >> This is only a tiny server (HP MicroServer) on a home LAN. > > > > http://www.amazon.com/APC-Back-UPS-shutdown-software-UPS- > BE350G/dp/B001985SWW/ > > Thanks, I'll look into that. > > >> I'm sure you are right, as I know nothing at all about power supplies. > >> But surely computers actually use DC, > >> so couldn't my torch-battery device just supply the PC > >> components directly? > > > You will either need many different batteries for the different voltages > > (1.2, 3.3, 5, 12, -12, -5) or a DC ATX power supply (not cheap and not > > very powerful until the 48V input variety) > > Surely one 12v battery would do? Actually not. You need both positive and negative voltages. You cannot just use a 12v battery with a voltage divider resistor network. And because the voltages needed have to be precise, you really need a properly regulated power supply. Like Jason said, it would be a 48VDC input unit and will cost you many times what a cheap UPS would cost. > It is only meant to last for 30 seconds or so, > so wouldn't reducing the voltage be easy enough? > I repeat that I don't know what I'm talking about ... > -- 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