Patent ID: 7113413

Claim:
A controller for a forward converter, the forward converter having a transformer, containing a primary coil in a primary circuit and a secondary coil in a secondary circuit; the controller comprising: a primary power device coupled to the primary coil in the primary circuit; a resonant reset capacitor coupled in parallel with the primary power device, wherein the resonant capacitor and the primary coil have a primary resonant cycle; one or more secondary power device in the secondary circuit; and a control logic, coupled to the primary power device and to at least one of the secondary power devices, wherein the control logic is capable of turning on the primary power device for a time essentially equal half of the primary resonant cycle; the control logic is capable of reversing a polarity of a voltage across the primary coil to keep an average of a magnetizing current in the primary coil essentially zero; and the forward converter is operable to transfer energy from the primary coil to the secondary coil when the primary power device is in a conductive state.