![](https://zhelectronics.com/wp-content/uploads/2022/05/Relay-module-300x185.png)
Board
![Grace](https://zhelectronics.com/wp-content/uploads/2022/05/avatar-150x150.png)
Working principle of relay module
When the relay works, the electromagnet is energized, and the keeper is drawn down to make D and E contact, and the working circuit is closed. The electromagnet loses its magnetism when it loses power, and the spring pulls the keeper up to cut off the working circuit. Therefore, a relay is a switch that uses an electromagnet to control a working circuit.