Weak current power load overvoltage protection circuit

Abstract

The invention discloses a weak current power load overvoltage protection circuit comprising AC commercial power, a step-down rectification module, a voltage stabilization module, an overvoltage detection module and a control module. The AC commercial power enters the input end of the step-down rectification module. The step-down rectification module outputs voltage after step-down rectification to the voltage stabilization module. The voltage output end of the voltage stabilization module is connected with the voltage detection module. The voltage detection module is connected with a load through the control module. According to the weak current power load overvoltage protection circuit, the power supply loop of the weak current power load is improved, intelligent control of the output end is realized by using the mode of combining a voltage sampling circuit and a relay element, automatic regulation is performed in case of overvoltage without disconnecting the power supply loop, and the voltage flowing through the load is reduced by the mode of increasing voltage dividing resistance so that the weak current power load overvoltage protection circuit has the advantages of high degree of intellectualization and stable performance without disconnecting load work in comparison with the conventional fuse wire, the air circuit breaker, the voltage dependent resistor and other protection devices.

Description

technical field [0001] The invention relates to an overvoltage protection circuit, in particular to an overvoltage protection circuit for weak electric power loads. Background technique [0002] With the continuous development of the power industry, more and more household appliances have entered the homes of ordinary people, especially the rapid development of the electronics industry, from lighting fixtures to refrigerators, air conditioners, and electric vehicles that have been continuously promoted in recent years. , induction cooker, it can be said that the stability of the home grid is directly related to people's daily life, and when the power line is transmitted to the home grid, electromagnetic interference, grid fluctuations, etc. often occur, resulting in overvoltage of the electrical load, so it is necessary Provide effective protection for such electrical equipment against overvoltage conditions. [0003] Overvoltage protection refers to a protection method tha...

AI Technical Summary

Problems solved by technology

The overvoltage detection circuit is composed of the first Zener diode, the second Zener diode, the third resistor and the fourth resistor. When the voltage at the input terminal of the DC power supply is higher than a certain value, the NPN transistor is turned on, and the voltage signal line is connected to the power management IC. , the power management IC can turn off the power supply according to the conduction of the voltage signal line to achieve the purpose of overvoltage protection and prevent the circuit from being damaged in the subsequent stage. It uses the power management IC to realize the overvoltage protection function, and its control cost is relatively high. limited

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