Study On A High Performance Multiple Output Power Supplies With New Driving Schemes For SRs

Based on the thorough investigation of the post-regulation and efficiency in multiple output switching-mode power supplies, an optimal combination topology for multiple output switching converter is presented in this thesis, which is consisted of forward converter with active clamp (FAC), synchronous rectification(SR) techniques and magnetic amplifier technique (magamp). AC small signal model and the operating principle of Forward converter with active clamp are analyzed in this paper. The superiority of FAC is obtained by comparing three typical kinds of methods of magnetic reset for Forward converters.With the stringent requirement of low output voltage and high output current, semiconductor diode is necessarily replaced by Synchronous Rectifier to minimum voltage drop. Because the existed driving schemes can not drive SRs properly, two novel driving schemes for synchronous rectifiers in magnetic amplifier post regulating circuit are proposed in this paper. The design and analysis of magnetic amplifier is illustrated . Finally, two prototypes of the proposed converters were built and fully tested to verify the theory analysis.