A New Full Resonant ZCS Forward Converter Having Wide ZCS Domain

Abstract

A new full resonant ZCS forward converter intended to improve undesirable performances of the conventional ZCS converter is proposed and many of operational items, such as ZCS domain, amplitude variation, efficiency, dynamic load effect and cross regulation, are successfully confirmed by experiments and theoretical analysis. The converter is possible to get ZCS action exploiting a L-C series resonant circuit putting in parallel with the transformer and a small inductance putting in series with the transformer. It is shown that the new converter is applicable to the power supplies for which good performances with respect to dynamic load effect, noise and efficiency are requested, and has possibilities realizing low noise, high frequency operation and then miniaturization. Furthermore, the simplified design method which is useful on case of early step of designing converter is given.