JPS5894019U - transformerless power supply circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional example, FIG. 2 is a circuit diagram of an embodiment of the present invention, and FIGS. 3a and 3b are operational waveform diagrams of the same. Tr2. Tr3 is a transistor, ■8 is an AC power supply, D
B2 is a diode bridge, R4 and R6 are voltage dividing resistors, Z
D2 is a Zener diode, and C2 is a capacitor.

Claims (1)

[Scope of utility model registration request] a rectifier that connects a plurality of transistors in series by connecting the emitter of a first-stage transistor to the collector of a second-stage transistor, and performs full-wave rectification of an AC power supply voltage;
A series circuit of the above transistors is interposed between a smoothing capacitor that smoothes the output of the rectifier, and the output voltage of the rectifier is divided almost equally by the number of transistors connected in series. A voltage dividing resistor that generates a voltage is provided, a reference voltage generated by a Zener diode is applied to the base of a transistor whose emitter is connected to a smoothing capacitor, and a divided voltage generated by the voltage dividing resistor is applied to the base of another transistor. A transformerless power supply circuit in which the transistor near the rectifier is supplied with a high base voltage.