Thanks for the supporting information! Guess if a notebook could do it, so can a desktop, its just that the current requirement would be much higher. ----- Original Message ----- From: "Mark Newland" To: Sent: Thursday, January 03, 2002 10:02 AM Subject: Re: [EE]: Small UPS > I actually have a fullsized desktop PC that has a 12Vdc plug in the back. Can > hook it up directly to a 12V car battery. > > Anand Dhuru wrote: > > > 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" > > To: > > 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: 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