Function: Through multi contact design, a relay can simultaneously control the on/off of multiple circuits, significantly expanding control capabilities. Relays can amplify weak input signals into strong signals, enabling long-distance transmission. The input-output circuit achieves physical isolation through electromagnetic isolation, avoiding damage to the control circuit caused by high voltage and high current, while providing overload or short circuit protection function. It can be combined with other electrical components (such as sensors, controllers) to form an automation control circuit, achieving timed, remote control, or feedback control.