Ripple reduction for switch-mode power conversion

A power converter includes an isolated or a nonisolated current-doubler rectification circuit including two magnetic circuit elements, each magnetic circuit element formed with a primary winding and a voltage-sensing winding. The primary windings are coupled in series. The voltage-sensing windings are also coupled in series but with a coupling sense opposite from that of the primary windings. A properly sized inductor and capacitor are coupled in series with the voltage-sensing windings to produce a ripple-cancellation current with slope opposite to a net slope error of currents produced in the two magnetic circuit elements. The current-doubler rectification circuit is preferably coupled to a rectangular ac input waveform. By sensing a scaled voltage difference between two magnetic circuit elements, a very low level of output ripple is produced by the circuit with very low power losses over a range of operating conditions.