New Snubbers with Energy Recovery into a Local Power Supply

The general attributes governing the design of Local Power Supplies (LPS) circuits that are piggybacked on a lossless turn off snubbers are highlighted and analyzed. Based on the proposed general principles, new LPS circuits are presented. They are incorporated as part of a lossless turnon/turn-off snubber. The proposed snubber/LPS topologies serve two important functions: they help to achieve soft switching of the main switch and main diode at turn-on and turn-off and provide low voltage power source for the auxiliary circuitry such as IC controllers. Since all the switching processes are soft and the reactive energy is recycled (or outputted by the LPS), the losses of the main switch and main diode are significantly reduced. The theoretical analysis of the proposed circuits was verified by simulation and experimental results.