A zero voltage switching forward converter topology

A zero voltage switching forward converter topology is presented in this paper. The topology employs an auxiliary circuit. Only a few small rating components and devices are added. The merits of the proposed topology include: lossless switching independent of the input and load conditions, simple control and power circuitry, and ability to operate in either voltage or current mode control. A steady state analysis is presented and the design procedure is illustrated. A 100 W 300 kHz prototype zero voltage switching forward converter is built which shows an efficiency improvement of approximately 5% as compared to a conventional hard switching forward converter.