| 摘要 |
PURPOSE: To obtain a power-supply apparatus which can improve the input current distortion and which enhances the efficiency of a circuit by a method wherein the input current distortion is improved by a first DC power supply, an AC power supply is converted into a first DC output and the first DC output is converted into a second DC output by a second DC power supply. CONSTITUTION: A step-up chopper circuit which can improve the input current distortion is used as a first DC power supply E1. A stepdown chopper circuit is used as a second DC power supply so as to output a voltage in such a way that the voltage of the second DC power supply E2 is lower than that of the first DC power supply E1. Thereby, since electric power is supplied only to the first DC power supply E1 from an AC power supply AC, the input current distortion can be reduced sufficiently by the stepup chopper circuit. In addition, since a voltage lower than that supplied to a main amplifier 7b is supplied to a driving device 9, the loss in the drive device 9 can be reduced. In addition, a stable high-frequency output can be obtained. |
