| 摘要 |
PURPOSE:To reduce power consumption at the rise of power supply voltage and to save electric power by operating a rectifier device usually as a full-wave rectifier circuit, and at the rise of the power supply voltage, operating the device as a half-wave rectifier circuit. CONSTITUTION:When the voltage of an AC power supply 1 is a prescribed value or less, a signal is outputted from a control signal output terminal 83 of a decision circuit 8, so that a thyristor 7 is turned on. Thereby, the rectifier device 2 operates as a full-wave rectifier circuit and a DC output is obtained from an output terminal 6. When the voltage of the AC power supply 1 is the prescribed value or more, no signal is outputted from the control signal output terminal 83 of the decision circuit 8, so that the thyristor 7 is turned off. Consequently, the rectifier device 2 operates in the course of a diode 24, a capacitor 3, a resistor 4, and a diode 22 as a half-wave rectifier circuit only when the upper terminal of the AC power supply 1 is positive. Thus, the power consumption of a power transistor 51 is sharply reduced as compared with that of the full-wave rectifier circuit. |
