Patent ID: 6845019
Filing Date: 2005-01-18
Classification: H02M

Abstract:
1. A flyback converter, which provides an essentially constant output voltage independent of the size of a load, the flyback converter comprising: a transformer operable to change an input voltage to a predetermined level according to a winding ratio of a primary coil to a secondary coil; an output unit, coupled to the transformer, operable to rectify a voltage signal output from the transformer into a DC signal operable to drive the load; a switch, coupled to the primary coil of the transformer, operable to control an on/off state of a power at the primary coil according to an input switching control signal; a feedback unit, coupled to the transformer, operable to detect the voltage signal output by the transformer to the output unit, generating a feedback signal, detecting a switching current of the switch to correct the feedback signal, and outputting the corrected feedback signal, the feedback unit comprising: a switching controller, coupled to the feedback unit and to the switch, operable to receive an output signal of the feedback unit and generating a switching control signal, operable to control the operation of the switch.