Patent ID: 8208236
Filing Date: 2012-06-26
Classification: H02M

Abstract:
1. A power converter, comprising: a transformer, having a primary winding, a secondary winding, and at least one auxiliary winding, wherein the secondary winding is used for generating an output voltage provided to a load; a switch element; a control circuit, coupled to a control terminal of the switch element, for controlling on/off status of the switch element so as to control a primary current flowing through the primary winding; an over-current detecting circuit, for comparing the primary current with a current limit, and then controlling the control circuit to turn off the switch element if the primary current is greater than the current limit; and a compensation signal generating circuit, coupled between the auxiliary winding and the over-current detecting circuit, for providing an adjustment value to calibrate the current limit according to an output of the auxiliary winding without referring to any signal outputted by the secondary winding when the switch element is turned on; wherein when the switch element is turned on, the adjustment value varies with time.