12v dc to dc inverter schematics
Yes, you can do it with a UC3843 or other PWM chips (such as TL494, for instance, although I prefer the current-mode UC3843).
Do you need isolation between the input and output? If you do, you will need a transformer and build a forward converter (you can get away with a flyback at this power level, too).
If no isolation is required, then a simple boost will do the trick. Let me know, I can help with schematics/ calculations.
VVV