| 摘要 |
PROBLEM TO BE SOLVED: To suppress the DC component and the even order harmonics of an input current from an AC power supply without increasing the cost and without requiring an intricate adjustment. SOLUTION: A power supply comprises means 10 for detecting the average value of the voltage Vc1 across a smoothing capacitor C1 and outputting a first detection voltage Vk proportional to the average value, and means 11 for detecting the average value of the voltage across a second switching element Q2 and outputting a second detection voltage Vj proportional to the average value. An on/off control section 1 controls the on period of first through fourth switching elements Q1-Q4 to be equalized depending on the first and second detection voltage Vk, Vj. According to the circuitry, the DC component and, the even order harmonics of an input current Is can be suppressed without causing cost increase incident to extra reactance for chopper or extra insulating transformer and without requiring an intricate adjustment. |
