hi again.. just to update my experience.. still the same situation..
I tried yesterday an irf840 and another diode BY..(something.. don't remember)
It seemed it worked better, with more volume, but still far from the result..
I think I'll try now to separate the power section and build the smps. uhm...
the inductor is still getting warm too, while the mosfet seems to be more colder respect to 740?!?

it's very difficult to find inductors here, but I don't want to buy one from internet and pay 3€ of shipment for a 1€ component.. damn...

ok, keep the calm... how McGyver would find the solution? (he's got only a knife, a stick, a chewingum, and distilled water)
