A low-cost, low-loss active voltage-clamp circuit for interleaved single-ended forward PWM converter

A scheme to effectively clamp the peak primary switch voltages in an interleaved single-ended forward power converter and properly reset the power transformers introducing virtually no losses is introduced. The scheme employs the switched snubber concept. No additional gate-drive logic and driver are needed. The scheme can be easily implemented using commercially available PWM chips with alternating gate-drive signals. A low-cost implementation of the scheme, and hardware results from a 5 V, 750 W prototype circuit are presented