intermediate relay: KM (common symbol, non-national standard) 【 (intermediate relay) 】
Relay (Relay), also known as relay, is an electronic control device, it has a control system (also known as the input loop) and the controlled system (also known as the output loop), usually used in automatic control circuit, it is actually a small current to control the larger current of an \"automatic switch\". Therefore, it plays the role of automatic regulation, safety protection and conversion circuit in the circuit. The relay coil is represented in the circuit by a long box symbol.
intermediate relay, English is :intermediate relay, mainly used in the control loop, it can increase the number of contacts and capacity, and can also complete such as: interlock circuit, normally open to normally closed control loop commonly used functions.