Filter protective circuit for house electric appliance

Abstract

The invention discloses a filter protection circuit of a household appliance. The filter protection circuit is arranged in the electrical control system of the household appliance and connected between a single-chip microcomputer of the electrical control system and a signal detection circuit; The inductance coil and the resistor between the signal detection circuit, the voltage regulator tube connected between one end of the inductance coil and the ground, and the first capacitor connected between the other end of the inductance coil and the ground. Preferably, a second capacitor connected in parallel to both ends of the voltage regulator tube is further included, that is, the voltage regulator tube and the π-shaped filter are connected in parallel. Wherein, the inductance coil is a PFC inductance coil. The invention can be widely used in household appliances such as AC frequency conversion washing machines, refrigerators or air conditioners, and can reduce the interference to detection circuits and single-chip microcomputers. When overcurrent, overvoltage or high temperature occurs, the safety of the inverter circuit can be guaranteed through the single-chip microcomputer. .

Description

technical field [0001] The invention relates to electrical control technology of household appliances, in particular to a filter protection circuit of household appliances. Background technique [0002] With the development of society and technology, the application of household appliances such as washing machines, refrigerators, and air conditioners is becoming more and more popular. [0003] The traditional fully automatic pulsator washing machine consists of a casing, a mechanical support device installed between the casing and the outer cylinder, an inner drum installed in the outer cylinder, a motor and its transmission device installed between the casing and the outer cylinder, and an installation It is composed of the inlet and outlet mechanism on the casing and the electrical control system. Its electrical control system includes a computer program-controlled circuit. So far, the variable frequency drive power of AC variable frequency washing machines is mostly con...

AI Technical Summary

Problems solved by technology

[0012] In the described prior art, since the signal from the signal detection circuit BC2 is directly connected to the pin of the single-chip microcomputer IC1, if there are more circuit interferences, these interferences will directly enter the single-chip microcomputer IC1, causing interference to the single-chip microcomputer IC1, which is too strong The interference signal will also cause damage to the microcontroller

After strong interference causes MCU damage or program confusion, it can no longer respond to protection detection and other signals. When overcurrent, overvoltage or overtemperature occur, the safety of the inverter circuit cannot be guaranteed.

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