Hello

:-D
Does anybody know a power supply to be used for PC that uses DC-DC converter as a substitute? I don't want to use an inverter. Any ideas on this?
You could try Opus Solutions. A number of mp3car.com forum members are using these:
http://www.opussolutions.com/
http://pinouts.ru/pin_Power.shtml I've used this information to power an AT motherboard off of sealed lead acid batteries but I'm sure ATX is just as easy. I used a capacitor to delay the rise time of the Power Good signal relative to the others so it was actually consistent, otherwise it refused to POST. I found this forum by searching for something totally unrelated too hehe.