Patent ID: 8901839

Claim:
A two-switch flyback power supply device, comprising: a transformer having a primary winding and a secondary winding to feed a load; a pair of electronic switches alternatively switchable on and off to connect the primary winding of said transformer to an input line to feed said primary winding of said transformer, wherein at least one of said electronic switches has a control electrode floating with respect to ground; a capacitive voltage divider arranged between said input line and the ground of the two-switch flyback power supply device, with the dividing point of said capacitive voltage divider connected to an intermediate point of said primary winding of said transformer; and an auxiliary secondary winding in said transformer, said auxiliary secondary winding feeding the control electrode of said at least one of said electronic switches, wherein one of the ends of the auxiliary secondary winding is connected to the gate of the electronic switch having the control electrode floating with respect to ground, wherein said at least one of said electronic switches is interposed between said input line and the primary winding of said transformer, and wherein the other of said electronic switches is interposed between the primary winding of said transformer and the ground of the circuit.