hi, im a newbie in electronics, and i need some help from you guys to point me in the right direction

im trying to convert 8.4v to 6.4v (2 li-ion to replace 4 AA) in a circuit that demand high amps (up to 12A sometimes) and im having a hard time to do so.

the first option ive found, are some "ready" switching regulators sold to RC helicopters, and others stuffs.

but i was thinking in doing one myself. cause i actually don't need a "full-featured" switching regulator, but, lets say, a "75% duty" switching regulator, as i don't really need steady-same voltage output, so no "feedback" needed for output, only about 2v drop from source voltage, with a good efficiency.

so, my main question, this is possible? a 555 and a power mosfet can do such thing?

tnks in advance.

 

Forget the 555, I would go for one of the synchronous recitifier controller IC driving external FETs. You can size the FETs and parallel them as needed to get all the current you want. There is also simple current limiting built in.

I can't remember the part numbers, just do search for synchronous rectifier controller.

 

tnks bountyhunter; i will look into it