JPS61205288U

JPS61205288U -

Info

Publication number: JPS61205288U
Application number: JP8809585U
Authority: JP
Priority date: 1985-06-11
Filing date: 1985-06-11
Publication date: 1986-12-24
Also published as: JPH0336222Y2

Description

[Brief explanation of drawings]

第１図は本考案に係るスイツチング電源の電気
回路図、第２図ａ，ｂ及び第３図ａ，ｂは本考案
に係るスイツチング動作を説明するための各部の
電圧波形図、第４図は本考案に係るスイツチング
電源の出力電流―出力電圧特性図、第５図は従来
のスイツチング電源の電気回路図、第６図ａ及び
ｂは同じくその過電流検出抵抗の両端に生じる電
圧波形図、第７図は同じくその出力電流―出力電
圧特性図である。１……スイツチング素子、２……変圧器、２１
……第１の巻線、２２……第２の巻線、２３……
第３の巻線、２４……第４の巻線、１０……過電
流保護回路、１０１……積分回路、１０２……比
較器、１０３……抵抗器。 Fig. 1 is an electric circuit diagram of a switching power supply according to the present invention, Figs. 2 a, b and 3 a, b are voltage waveform diagrams of various parts to explain the switching operation according to the present invention, and Fig. 4 is an electric circuit diagram of a switching power supply according to the present invention. Figure 5 is an electrical circuit diagram of a conventional switching power supply; Figures 6a and b are diagrams of voltage waveforms generated across the overcurrent detection resistor; Similarly, FIG. 7 is the output current-output voltage characteristic diagram. 1... Switching element, 2... Transformer, 21
...First winding, 22...Second winding, 23...
3rd winding, 24... Fourth winding, 10... Overcurrent protection circuit, 101... Integrating circuit, 102... Comparator, 103... Resistor.

Claims

[Claims for Utility Model Registration] (1) A switching element is connected to the first winding of a transformer to which DC input voltage is supplied, and the first winding and third winding of the transformer are used. In the switching power supply, the DC input voltage is switched by applying positive feedback from the output side to the input side of the switching element to cause a blocking oscillation operation, and the switching output is taken out from the second winding of the transformer, A fourth winding is provided in the transformer, and the on-time width and input voltage of the switching element are monitored by a voltage signal generated in the fourth winding of the transformer, and an overvoltage is determined based on the monitoring signal. A switching power supply comprising an overcurrent protection circuit that controls the driving time width of the switching element during load. (2) The overcurrent protection circuit includes an integrating circuit that integrates the voltage generated in the fourth winding of the transformer during the ON period of the switching element, and a a circuit that superimposes a voltage signal obtained by rectifying and smoothing the voltage generated in the line;
2. The switching power supply according to claim 1, further comprising a circuit for comparing the superimposed voltage signal of this circuit with a reference voltage signal. (3) The reference voltage signal is given as a superimposed voltage signal of a reference voltage given from a reference voltage source and a DC output voltage signal obtained by rectifying and smoothing the output taken out to the second winding. A switching power supply according to claim 1 of the utility model registration claim, characterized in that: (4) The overcurrent protection circuit converts the comparison output into
The switching power supply according to claim 2 or 3, wherein the switching power supply is input to a drive circuit that drives and controls the switching element as a logical sum with an output signal of a constant voltage control circuit.