A novel PFC circuit using ladder type filter employing only passive devices

For various rectifier circuits such as those for consumer electronics and appliances, rectifier circuits of the capacitor input type are generally used. It is known that such rectifier generates various harmonics in the power system. To improve those harmonic problems, various PFC circuits have been proposed so far. Among these, Takahashi have proposed a PFC scheme using a LC filter without switching devices. This method makes a PFC effect by widening conduction period using the operations of capacitors and inductor. On the basis of this scheme, we propose another PFC circuit. This method attempts to improve the input current, towards satisfactory waveform by using a novel ladder type filter.