JPS61205291U

JPS61205291U -

Info

Publication number: JPS61205291U
Application number: JP8918785U
Authority: JP
Priority date: 1985-06-11
Filing date: 1985-06-11
Publication date: 1986-12-24

Description

[Brief explanation of the drawing]

第１図は本考案の一実施例の回路図、第２図は
従来例の回路図、第３図および第４図は前記実施
例の動作説明に供する前記第１図の回路の一部の
回路図、第５図ないし第８図は前記動作説明のた
めの各部の信号波形図である。１……交流電源、１５……負荷、１５０……全
波整流回路、６０，９０……抵抗、７０，１００
……コンデンサ、８０，１１０，１２０……ダイ
オード、１３０，１４０……トランジスタ、１６
０……電源切換用スイツチ。 FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a circuit diagram of a conventional example, and FIGS. 3 and 4 are part of the circuit of FIG. 1 for explaining the operation of the embodiment. The circuit diagrams and FIGS. 5 to 8 are signal waveform diagrams of each part for explaining the operation. 1...AC power supply, 15...Load, 150...Full wave rectifier circuit, 60,90...Resistance, 70,100
... Capacitor, 80, 110, 120 ... Diode, 130, 140 ... Transistor, 16
0...Power selection switch.

Claims

[Scope of utility model registration request]

A full-wave rectifier circuit is provided, and a series circuit of a first resistor and a power supply voltage switching switch is connected between the rectified output terminals of the full-wave rectifier circuit, and a first capacitor, a first diode, and a second resistor are connected. A second capacitor and a second diode are connected in series in this order so that the polarities of both diodes are in the same direction, and a third capacitor and a second diode are connected in parallel to the first capacitor and the first diode. A diode is connected so that its polarity is opposite to that of the first and second diodes, and a collector of the transistor is connected in parallel to the series circuit of the first diode, second resistor, and second capacitor. A rectifier circuit comprising an emitter connected and a base of this transistor connected to a connection point between the first resistor and the switch.