| 摘要 |
PROBLEM TO BE SOLVED: To extend the operation life of a high frequency reverse-current checking unit, improve the performance of the high frequency reverse-current checking unit, reduce the size of a power supply apparatus, improve a total circuit efficiency, improve an input power factor and suppress input current harmonics by a method wherein a power loss which is produced by the high frequency reverse-current checking unit consisting of, for instance, a diode reduced and the heating of components caused by the power loss is reduced. SOLUTION: The DC output of a rectifier DB is smoothed by a smoothing capacitor C1 through a diode D3 which checks a high frequency reverse-current and converted into an AC high frequency power by an inverter circuit. The AC high frequency power is supplied to a discharge lamp La through a capacitor C3 and an inductor L2 and a part of it is fed back to the point between the diode D3 and the rectifier DB through an impedance element Z1. Diodes D4 and D5 are provided between the input terminal of the rectifier DB and the cathode terminal of the diode D3. |
