An overvoltage protection circuit

Abstract

The invention provides an overvoltage protection circuit which comprises a voltage division circuit, a comparator, a counter and a logic control output module. Voltage division voltage output by the voltage division circuit is introduced into a single chip microcomputer through Vesnse pins of the single chip microcomputer. The comparator is positioned in the single chip microcomputer and compares the voltage division voltage with reference voltage in the single chip microcomputer, when the voltage division voltage is higher than the reference voltage in the single chip microcomputer, a first comparative result is output, and otherwise a second comparative result is output. The counter is positioned in the single chip microcomputer, starts to count when receiving the first comparative result and outputs a first counting result. The counter starts to count when receiving the second comparative result and outputs a second counting result. When the first counting result reaches a preset first value, the logic control output module outputs a disconnecting instruction to enable a switching element connected with loads to be disconnected, or when the second counting result reaches a preset second value, the logic control output module outputs a communicating instruction to enable a switching element connected with loads to be communicated. The overvoltage protection circuit is simple, and fault protection is avoided while overvoltage protection is achieved.

Description

technical field [0001] The invention relates to the technical field of protection devices, in particular to an overvoltage protection circuit. Background technique [0002] With the improvement of the automation of electrical equipment and the complexity of the structure of the power system, when the system power supply or some key points have voltage abnormalities, such as undervoltage or overvoltage faults, it may cause loss of function of the power equipment or damage to the power system. The entire system will be affected, and in severe cases, the equipment will be damaged and economic losses will be caused. Therefore, voltage detection and protection are generally performed on the input power supply or some collection points, especially overvoltage and undervoltage protection. [0003] The so-called overvoltage protection means that when the power supply voltage of the protected line is higher than a certain value, the protector cuts off the line; when the power supply ...

AI Technical Summary

Problems solved by technology

[0010] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an overvoltage protection circuit, which is used to solve the problem that the overvoltage protection circuit in the prior art is too complicated and has false protection

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