At Sat, 02 Jul 2011 14:52:27 +0200 CentOS mailing list <centos at centos.org> wrote: > > Emmanuel Noobadmin wrote: > > >> It seems to me that it should be possible > >> to have a simple, torch-battery operated, system > >> which will keep the machine alive long enough > >> to make a graceful exit. > > > Like others have suggested, a cheap UPS is the way to go. > > I'm convinced. > Could you (or anyone) suggest a cheap UPS? > This is only a tiny server (HP MicroServer) on a home LAN. > > > The problem > > with your idea is that you'll need a DC to AC inverter that can handle > > the output current required by your server and something to hold the > > batteries (you'll need more than one because attempting to draw a huge > > current from a normal battery will either kill it or at the very least > > cause it to have a shorter than expected capacity) and everything > > together, it's probably going to cost more in both money and time to > > have this thing. > > 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? A PC uses several *different* DC voltages: +12, +5, +3.3, and several others and they need to be *precise*. Some of these are not an exact multiples of the standard 1.5V Carbon-Zinc cells typicaly used in torch batteries. > > Many decades ago I went to lectures at university given by Fred Hoyle > (famous at the time for a TV series where he said God was unnecessary). > The lectures (on thermodynamics) were not really very good, > but they were interesting because Fred Hoyle was slighly paranoid, > and believed evil capitalists were foisting unnecessary devices on us. > > One of his pet theories was that cars did not need huge accumulators, > but could be started with a torch-battery. > > Another was that incandescent bulbs were deliberately made to fail > after a certain time. > > Another was razor blades, which according to him could easily last for ever. > > One interesting idea was that instead of nuclear power stations > it would be cheaper, and give the same energy, to plant trees > in a strip around the equator (I forget how wide). > > > > > > -- 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