Patent ID: 8885364

Claim:
A flyback converter with primary side and secondary side control, the flyback converter comprising: a transformer having a primary winding, a secondary winding and an auxiliary winding electromagnetically coupled to each other, a secondary-side feedback unit operatively connected to the secondary winding and the primary winding, the secondary-side feedback unit comprising an isolated signal transceiver device and an error amplifier electrically connected to an output port of the flyback converter, the isolated signal transceiver device comprising a signal transmitter at a secondary side and a signal receiver at a primary side, the signal transmitter sends a secondary feedback control signal to the signal receiver through an isolation layer, wherein the secondary feedback control signal is in response to a load condition of the flyback converter, and a feedback control unit electrically connected to the auxiliary winding and the signal receiver such that the secondary-side feedback unit sends information of load condition of the flyback converter in isolation matter to the feedback control unit, wherein the feedback control unit receives the secondary feedback control signal sent from the isolated signal transceiver device for feedback control when the flyback converter is operated in heavy load conditions; wherein the feedback control unit receives a primary feedback control signal sensed by the auxiliary winding for feedback control when the flyback converter is operated in light load conditions.