Patent ID: 7859859

Claim:
A method for converting power via a transformer from an input source for delivery to a load comprising: providing a primary power circuit including a primary winding of the transformer, at least one primary switch connected to drive the primary winding, a clamp capacitor, and a clamp switch to connect the clamp capacitor to the primary winding; providing secondary circuitry including a secondary winding of the transformer and rectification circuitry connected to the secondary winding and to deliver a rectified output voltage to the load; providing a switch controller to operate the at least one primary switch and the clamp switch in a series of converter operating cycles; each converter operating cycle being characterized by a current in the secondary winding varying between a maximum value and a minimum value; detecting when the current in the secondary winding essentially reaches the minimum value and generating a first signal in response; and sampling a voltage in the primary power circuit in response to the first signal as a measure of the output voltage.