an i directly give the stepped down AC voltage of 15V/12?

[sramgrk]

MOSFET Supply doubt

Can i directly give the stepped down AC voltage of 15V/12V from the transformer to the source/drain of the MOSFET?

 

[dick_freebird]

MOSFET Supply doubt

That would depend on the MOSFET, and the desired outcome.

Power MOSFETs are not symmetric and they would stand off
the voltage during one (say, positive VD-VS for NMOS) half
cycle but conduct through the body-drain diode when drain
goes negative (seldom a good thing).

There are "photoMOS" type solid state relays that take two
MOSFETs, "butterfly" them about the S/B terminal and pump
the two gates (relative to S) with a photoelectric current
from a LED.

The butterfly arrangement gives symmetric voltage blocking
(at cost of ~2X Rds(on) and the optical-electrical path gives
galvanic isolation between control and power domains.

 

[sramgrk]

MOSFET Supply doubt

@dick_freebird:
I hav planned to use IRF 450...wat abt that???