Cap -- In a computer, the majority of the power consumed is at 5 volts. As an indication, a 200W AT power supply I have has the following output rating: +12V 8A -12V 0.5A +5V 23A -5V 0.5A Dropping a 12-volt battery to 5 volts with a linear regulator feeding 10 amps would dissipate 70 watts in the regulator alone -- more than what's required to power the entire computer. A switching supply is necessary to gain any savings over an inverter. And the 12-volt nominal battery voltage would probably have to be regulated before feeding it to the computer's 12-volt line. All in all, this is no small task unless you're in the power supply business. Regards, Karl At 11:24 AM 5/8/2001 -0400, you wrote: >Hi Travis, > >I like your idea and plan on eventually building a similar backup system. >What I would like to know is how can I go about eliminating the 12V DC/120V >AC inverter in your system. Since the computer ultimately runs on DC power, >how can I just run it from the 12V batteries? Then a charger with an >automatic cutoff when the batteries are fully charged, could be connected >permanently to the 12 V batteries so they are always kept fully charged. If >the 120V AC mains go down as is happening in California, the computer would >not know it happened because it is running off the batteries. They will of >course run down eventually but that problem can be taken care of with a >generator. I have an 800 Watt Honda 120V AC generator that also has a 12 V DC >output that could be used to keep the batteries charged until the mains came >back on. I hope somebody can tell me what to do inside my computer to convert >it to run on 12V DC from the batteries. __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>