a power circuit

Abstract

An embodiment of the invention discloses a power supply circuit. The power supply circuit is used for solving the problem of large voltage stress of a rectifier caused by a high transient impact current due to zero voltage of a transient clamp capacitor when a power supply circuit is turned on. The power supply circuit comprises MOS transistors Q1-Q5, capacitors C1-C2, a resistor R, an inductor L and a transformer rectifying circuit. Before the power supply circuit is turned on, the capacitor C1 is pre-charged by an auxiliary power supply; when the voltage of the capacitor C1 is stabilized, the entire power supply circuit is started; afterwards, when Q1 and Q4 are turned on, Q2 and Q3 are turned off, and when Q2 and Q3 are turned on, Q1 and Q4 are turned off; the transformer rectifying circuit transforms a first AC inputted when Q1 and Q4 are turned on or when Q2 and Q3 are turned on into a second AC and rectifies the second AC into a DC; Q5 controls the capacitor C1 not to discharge; and C1 is used for clamping a rectifier in the transformer rectifying circuit. The embodiment of the invention can be implemented for reducing the voltage stress of the rectifier in the transformer rectifying circuit.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a power supply circuit. Background technique [0002] The power supply circuit is an indispensable circuit in the electronic circuit, and the transformer rectification circuit is an indispensable circuit in the power supply circuit. In order to reduce the voltage stress of the rectifier tube in the rectifier circuit, a clamp capacitor is generally connected to the output end of the transformer rectifier circuit. But at the moment when the power supply circuit is working, since the initial voltage of the clamping capacitor is zero, the instantaneous inrush current of the clamping capacitor is large, resulting in a large voltage stress on the rectifier tube, which is easy to cause damage to the rectifier tube. Contents of the invention [0003] The embodiment of the present invention discloses a power supply circuit, which is used to solve the problem that the voltage stress...

AI Technical Summary

Problems solved by technology

[0003] The embodiment of the present invention discloses a power supply circuit, which is used to solve the problem that the voltage stress of the rectifier tube is relatively high due to the large instantaneous surge current caused by the voltage of the clamping capacitor being zero at the moment when the power supply circuit is started.

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