Switch power supply and rectifying circuit

Abstract

The invention discloses a switch power supply and a rectifying circuit. The rectifying circuit comprises a first controllable switching tube, a second controllable switching tube, a third controllable switching tube, a fourth controllable switching tube, a first sampling comparison module, a second sampling comparison module, a first driving module and a second driving module. The four controllable switching tubes are respectively provided with an internal equivalent diode or an anti-parallel diode. The two sampling comparison modules are respectively used for conducting sampling on the positive half circle voltage and the negative half circle voltage and conducting comparison on the sampling voltage of the positive half circle of an alternating current power supply and the reference voltage value. The first driving module is used for controlling the switch-off of the second controllable switching tube and the third controllable switching tube when the sampling voltage of the positive half circle of the alternating current power supply is smaller than the reference voltage value. The second driving module is used for controlling the switch-off of the first controllable switching tube and the fourth controllable switching tube when the sampling voltage of the positive half circle of the alternating current power supply is smaller than the reference voltage value, and controlling the switch-on of the first controllable switching tube and the fourth controllable switching tube when the sampling voltage of the positive half circle of the alternating current power supply is larger than the reference voltage value. The switch power supply can improve the switching efficiency of the alternating current power supply and is simple in the control method.

Description

technical field [0001] The invention relates to the field of voltage conversion, in particular to a switching power supply and a rectifying circuit. Background technique [0002] With the development of science and technology, the power demand of electrical equipment is gradually increasing, the output power of a single switching power supply is also increasing rapidly, and the conversion efficiency requirements are getting higher and higher. [0003] Such as figure 1 As shown, the diode rectifier bridge, as a power component, realizes the conversion of the input AC voltage into the output DC voltage, and can be applied to various equipment with AC rectification. However, due to the large voltage drop of the PN junction of the diode rectifier bridge, it directly affects the conversion efficiency of the power supply. In order to improve the conversion efficiency of the power supply, the first thing people think of is to replace the PN junction diode bridge stack with a MOS ...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a switching power supply and a rectifier circuit with high conversion efficiency and simple control method in view of the above-mentioned defects of low conversion efficiency or complicated control method in the prior art

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