INPUT RECTIFYING CIRCUIT FOR SWITCHING POWER SUPPLY UNIT

摘要

PROBLEM TO BE SOLVED: To provide a stable and highly-efficient rectifying circuit for switching power supply unit by suppressing harmonics with AC power supply as an input in a boost half-bridge type (BHB type) switching power unit. SOLUTION: In the boost half-bridge type (BHB type) switching power supply unit, a bridge rectifying circuit at the forward stage of an input side choke coil is formed out of a pair of high-speed diodes and a pair of diodes or MOSFETs disposed with capacitors in parallel. As a result, the number of the diodes in a current path through which high-frequency current component and low-frequency current component pass can be reduced, and electric energy consumed by the diode, thus providing the highly efficient rectifying circuit for highly efficient rectifying circuit for power supply unit.