Electronic relay
An electromagnetic relay is a device that moves a contact by energizing a coil in a relay by electric magnetic action when an electric current flows. It is commonly used in areas such as elevators and pneumatic devices. Before computers became more sophisticated, they were used a lot, but there are a number of drawbacks, such as the number of effective usage and accuracy of about 25,000 times. There are 8 pins, 11 pins, and there are 20 pins, but most use 8 pins and 11 pins. In the case of 8 pins, the power is 2 and 7, the a contact is 1-3,8-5, and the b contact is 1-4,8-6. In addition to these, there is also a flicker relay with timer function.