| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power circuit that improves a power factor, increases power conversion efficiency, and reduces the number of circuit configuration components. SOLUTION: A primary side functions as a converter having primary first and second series resonance circuits and a primary voltage resonance circuit. A primary first series resonance frequency, where the frequency is controlled by a choke coil PCC functioning as an inductor L3 and a primary series resonance capacitor C2, is set to nearly two times larger than that of a primary second series resonance frequency, where the frequency is controlled by a leakage inductor L1 of a converter transformer and the primary series resonance capacitor C2, for ZVS operation. There is an active clamp circuit comprising a capacitor Cc for voltage clamp, and an auxiliary switching element Q2 for reducing the breakdown voltage of switching element Q1. A power factor improvement section adopts a voltage feedback system or a power regeneration system, and expands the continuity angle of a primary rectifying element Di, thus improving the power factor. COPYRIGHT: (C)2008,JPO&INPIT |
