My smps providing three voltages 12v, 4.2v and 5v. However transformer used here only providing two voltages 12&4, i m using 7805 to get 5v. My Mosfet 2N65 which I am using for switching heating even at no load. And on load it's getting too hot. What are the causes that MoSfet heating. Please help me troubleshoot this problem.