Patent ID: 7233505

Claim:
A flyback converter comprising: a primary side and a secondary side, said primary side having a primary winding and a switch both connected in series, said secondary side having a secondary winding, a MOSFET (metal-oxide-semiconductor field-effect transistor) having a source connected to the second winding and a drain connected to a load, a tertiary winding connected between a gate and the source of the MOSFET, a first resistor connected between the gate and the source of the MOSFET and between a first end of the tertiary winding and a capacitor, and said capacitor connected between said gate and a second end of said tertiary winding, wherein when said switch on said primary side is turned on, the gate voltage of the MOSFET is induced by the tertiary winding to be negative such that the MOSFET is turned off, wherein when said switch on said primary side is turned off, the gate voltage of the MOSFET is induced by the tertiary winding to be positive such that the MOSFET is turned on, and wherein said resistor connected between the gate and source of the MOSFET increases said negative voltage to thereby accelerate turning-off of said MOSFET to prevent power losses when said switch on said primary side is turned on, whereby when said switch of said primary side is turned on/off, the power energy at said primary side can be transferred to said secondary side in a flyback manner.