Overvoltage and undervoltage protective circuit based on three-end adjustable shunt reference source

Abstract

An overvoltage and undervoltage protective circuit based on a three-end adjustable shunt reference source comprises an undervoltage protective circuit, an overvoltage protective circuit and an output control circuit, wherein the undervoltage protective circuit, the overvoltage protective circuit and the output control circuit are connected in a power circuit, the undervoltage protective circuit is composed of a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, a capacitor C2, an audion Q1, a voltage-regulator diode DZ1 and a TLV431 chip U1, the overvoltage protective circuit is composed of a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor 10, a capacitor C3, a capacitor C4, an audion Q2, a voltage-regulator diode DZ2, a voltage-regulator diode DZ3 and a TLV431 chip U2, and the output control circuit is composed of a resistor R11, a capacitor C5, an MOS transistor Q3 and a diode D1. According to the overvoltage and undervoltage protective circuit, the TLV431 is utilized as the standard, overvoltage and undervoltage protection can be conducted on a power supply, power consumption is low, accuracy is high and reaction speed is high.

Description

technical field [0001] The invention relates to an electronic circuit, in particular to an overvoltage and undervoltage protection circuit based on a three-terminal adjustable shunt reference source, and belongs to the technical field of switching power supply voltage protection. Background technique [0002] When the power supply voltage of the switching power supply is lower or higher than a certain value of the normal working voltage, the power supply may not work properly or even be damaged. In order to solve the above problems, people have designed overvoltage and undervoltage protection circuits. At present, the commonly used overvoltage and undervoltage protection circuits use relays powered by another auxiliary power supply to control their on-off to achieve the purpose of protection. The response speed of the relay is slow, and an additional power supply is required to power the relay, which not only leads to increased power consumption, but also the protection of t...

AI Technical Summary

Problems solved by technology

The response speed of the relay is slow, and an additional power supply is required to power the relay, which not only leads to increased power consumption, but also the protection of the auxiliary power supply is also a problem

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