Buck converter with a new driving circuit in a TV power system

In this letter, a new buck converter of a TV power system is presented. First, we devised a driving circuit for an emitter-coupled type buck converter, by which it is possible to reduce the material cost of transformers and voltage stress of power device. Second, we adopted a hybrid oscillation technique. After self-oscillating mode feeds initial standby power, main power is provided by a forced oscillating mode and switching frequency is synchronized to that of horizontal deflection, which results in reducing picture noises and the size of power transformer. Third, a simple error amplifier is added in the feed-back loop to keep the output voltage constant. Finally, we showed that experimental values of our proposed converter agree well with the theoretical values.