| 摘要 |
PURPOSE: To enhance the input power factor, to decrease the distortion of the input current and to make the output variable by controlling the switching means on the side of the high voltage and the side of the low voltage, which are detected by current detecting means, by the control means, which is connected to the low voltage side of a rectifier means. CONSTITUTION: The input terminal of a rectifier circuit 12 as a rectifier means is connected to a commercial AC power supply E. A field-effect transistor Q1 as a switching means on the high-voltage side, a field-effect transistor Q2 as a switching means on the low voltage side and a resistor R as a current detecting means are connected between the output terminals of the rectifier circuit 12 in series. A control means 13, which is connected to the low voltage side of the rectifier circuit 12, controls the field-effect transistor Q1 on the high voltage side and the field-effect transistor Q2 on the low voltage side based on the current detected by the resistor R1. Thus, the input power factor is improved, the distortion of the input current can be decreased and the output can be made variable. |
