Abstract
For small capacity rectifier circuits such as those for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. In a certain application, it is necessary to obtain the lower output voltage, that is very difficult to realize such condition by using the passive elements only. In order to realize such condition, we propose a power factor correction scheme using a cycle-control and phase-control without high frequency switching devices. In this method of cycle control, improved input current wave can be obtained by widening conduction period. Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The results are confirmed by the theoretical and experimental implementations.
