12 V DC -> 220 V AC ?
To supply the PC...
What's the best solution (low costest)
- Using 12 V DC -> 220 V AC converter
and plug it to the classic alimentation of the PC
- Supply HDs, motherboards, CDROM, seppartly without AC->DC and DC->AC inverter.
I'm not quite sure I follow you on the "supply separately" part, since you're always going to supply these devices power separately (hence the many power connectors coming out of an AC power supply). But if you're going for the lowest cost for a car-only (or -mostly) situation, the best deal I've seen has been a DC-DC supply (e.g. http://scott.kincaid.net/ ). However, if you plan to use several hard drives and/or CD-ROM drives, this may not be able to provide enough power, and you may end up buying more than one, in which case an inverter my serve you just as well (so long as you're not too worried about appearance).