Safety protection circuit and method of door cover of washing machine

Abstract

The invention relates to a safety protection circuit and method of a door cover of a washing machine, belonging to the field of safety protection of the washing machine. The safety protection circuit comprises at least one main relay and a door cover switch circuit or an electronic door lock circuit, wherein the main relay is connected in series with a motor circuit of the washing machine; the door cover switch circuit comprises a door cover switch and a matched circuit thereof; the electronic door lock circuit comprises an electronic door lock and a matched circuit thereof; and the door cover switch or the electronic door lock is connected in series with a control circuit of the main relay. When the door cover or the electronic door lock is opened or unlocked, the main relay is opened so as to cut off a power supply of a motor. The invention ensures the safety of users through similar mechanical-type power interruption, thereby not only meeting the requirements for safety standards, but also saving the test cost and shortening the test period.

Description

technical field [0001] The invention relates to a safety protection circuit and method, in particular to a safety protection circuit and method for a door cover of a washing machine. Background technique [0002] At present, washing machines use a micro switch as a judgment method to detect whether the door cover is open. The micro switch is just a simple switch signal. In the running state of the washing machine, such as dehydration or washing operation, it is hoped that the motor can stop running after the cover is opened. In some cases, when it is detected that the door cover is opened, the washing machine control unit sends an instruction to stop the work of the motor. figure 1 It is a schematic diagram of the door switch detection circuit currently used in the washing machine. The door switch detection circuit includes a +5V power supply, resistors R904, R905 and R906, and the door switch detection circuit is connected with the washing machine control unit. When the do...

AI Technical Summary

Problems solved by technology

[0008] Regardless of whether the door lock method or the micro switch method is used, from the perspective of standard requirements, to ensure that the door cover is opened during the high-speed operation of the washing machine, the motor must be powered off, and this power failure is not sent through an electronic circuit such as the washing machine control unit. The implementation of the instruction must be a power failure in a mechanical state, otherwise the product must pass the electronic circuit evaluation CLASS B, and the related costs and test cycle of electronic circuit evaluation are relatively high

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