| 摘要 |
PROBLEM TO BE SOLVED: To obtain a power supply in which the harmonic distortion of input current is improved over a wide lad range only through the resonance operation of an inverter circuit, without requiring expensive circuit means. SOLUTION: An inverter comprises a smoothing capacitor C0 , connected through a diode D1 with the DC output terminal of a full-wave rectifier DB connected with an AC power supply, first and second switching elements Q1 , Q2 connected in series across the smoothing capacitor C0 and turned on/off alternately, a resonance circuit connected between the joint of the DC output terminal of the full-wave rectifier DB and the diode D1 and the joint of the first and second switching elements Q1 , Q2 , and a capacitor C5 connected across the diode D1 . The input current having a waveform which jumps abruptly at the time of zero-cross is generated under a heavy load, and a pause is generated at the time of zero-cross under a light load. |
