Pretty simple actually... the monitor. You'd still probably need an inverter
for the monitor, and even if you didn't there are still a variety of
peripherals that have different voltages, ie. printers, scanners, etc. While
this may sound crazy the easiest solution is an inverter, all of these
devices work with 120V AC. Aside from that inverter technology has
progressed amazingly in the past couple decades, it is no longer the huge
bulky, noisy and wasteful device it used to be. TTYL

> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Anand Dhuru
> Sent: Wednesday, January 02, 2002 22:52
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: [EE]: Small UPS
>
>
> This is something I've always thought about. Essentially what the PC
> requires are +/-12Volts, and +/- 5V. Why dont they come out with
> a standard
> for a 'power supply port'? Since the current requirement for the -ve
> voltages is minimal, wouldnt it make a lot of sense to just connect the
> motherboard to a battery thru proper rectifiers to block current when the
> power is present? The most expensive electronic stage in a
> conventional UPS,
> the inverter, could be completely eliminated. The battery could have an
> external charger, or the 'port' could have a source trickling
> back from the
> SMPS to charge it. The negative voltages could be derived from the battery
> as well.
>
> I do have a feeling i am missing something here, but what is it?
>
> Anand
>
> ----- Original Message -----
> From: "Peter Mcalpine" <pmcalpin@BIGPOND.NET.AU>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Wednesday, January 02, 2002 5:55 AM
> Subject: [EE]: Small UPS
>
>
> > Hi All and happy new year :)
> >
> > I want to make a small UPS, one that would be able to run my
> > PC for a little while if the power failed (enough so it can
> > shutdown it self down properly).
> >
> > 2 ways I have thought of doing it.
> > 1st would be a 240V to 12Vbattery back to 240V that can be run
> > in series with the incoming supply.
> > 2nd would be to modify the existing switch mode computer power
> > supply to include the battery.
> >
> > I would like to do the second method as that sounds easier :)
> >
> > Any suggestions or pointers to websites that may help me out?
> >
> > Thanks!
> > Peter Mcalpine
> >
> > --
> > http://www.piclist.com hint: To leave the PICList
> > mailto:piclist-unsubscribe-request@mitvma.mit.edu
> >
> >
> >
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>
>

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics