JPS6093492U

JPS6093492U - Switching power supply control circuit

Info

Publication number: JPS6093492U
Application number: JP18517383U
Authority: JP
Inventors: 博之三宅
Original assignee: 株式会社明電舎
Priority date: 1983-11-30
Filing date: 1983-11-30
Publication date: 1985-06-26
Also published as: JPS644307Y2

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

第１図及び第２図は各々スイッチング電源の制御回路を
示す回路図、第３図は本考案の一実施例に係るスイッチ
ング電源の制御回路を示す回路図、第４図は、パルス幅
制御回路の動作電圧の変化を、従来のものと本考案のも
とについて比較した結果を示すグラフである。２０・・・第１の整流回路、４・・・スイッチング素子
、５・・・スイッチングコイル、６・・・整流フィルタ
回路、７・・・負荷、８１・・・定電圧制御回路、８２
・・・パルス幅制御回路、９・・・第２の整流回路、９
０・・・定電圧回路、９２・・・ツェナーダイオード、
９３・・・始動用トランジスタ、９７・・・整流器とし
てのダイオード、９８・・・平滑用コンデンサ、９９・
・・抵抗、９４・・・平滑用コンデンサの電圧安定化用
のダイオード、ＩＯＡ・・・電源ライン。1 and 2 are circuit diagrams each showing a control circuit of a switching power supply, FIG. 3 is a circuit diagram showing a control circuit of a switching power supply according to an embodiment of the present invention, and FIG. 4 is a pulse width control circuit. 2 is a graph showing the results of comparing changes in operating voltage between a conventional device and the present invention. 20... First rectifier circuit, 4... Switching element, 5... Switching coil, 6... Rectifier filter circuit, 7... Load, 81... Constant voltage control circuit, 82
...Pulse width control circuit, 9...Second rectifier circuit, 9
0... Constant voltage circuit, 92... Zener diode,
93... Starting transistor, 97... Diode as a rectifier, 98... Smoothing capacitor, 99...
...Resistor, 94...Diode for voltage stabilization of smoothing capacitor, IOA...Power line.

Claims

[Scope of utility model registration request]

The DC voltage obtained by rectifying and smoothing the AC voltage in the first rectifier circuit is supplied to the switching transformer and the series circuit of the switching element, and the voltage on the secondary side of the switching transformer generated by the switching of the switching element is rectified and smoothed and applied to the load. In a control circuit for a switching power supply that controls a pulse signal for gate drive of a switching element generated by a pulse width control circuit in response to a load voltage, a power supply line for the first rectifier circuit and the pulse width control circuit; A constant voltage circuit including a starting transistor and a Zener diode for supplying base current to the starting transistor is provided between the switching transformer and a tertiary coil, and this tertiary coil is connected to a rectifier and a smoothing transformer. connected to the power supply line via a second rectifier circuit consisting of a capacitor, and providing a resistor on the output side of the rectifier for suppressing the peak value of the charging current of the smoothing capacitor;
A diode for voltage stabilization of the smoothing capacitor is provided between the output end of the second rectifier circuit and the cathode of the Zener diode so that the anode is connected to the output end of the rectifier circuit, At the time of starting, the starting transistor is turned on to supply the DC voltage from the first rectifier circuit to the pulse width control circuit as the operating voltage, and after the switching element starts switching operation, the voltage from the second rectifier circuit is supplied to the pulse width control circuit. A control circuit for a switching power supply, characterized in that the voltage is supplied to a pulse width control circuit as an operating voltage, and the voltage of a smoothing capacitor is limited to the sum of the voltages of the Zener diode and the diode.