An Electromechanical Relay (EMR) is a widely used switching device in electrical and electronic systems. It plays a crucial role in automating and controlling circuits, as well as providing protection in many applications. By understanding the components, working principles, and advantages of an electromechanical relay, we can gain insight into why it remains an essential component in various industries.

Components and Working Principle An electromechanical relay consists of three main components： an electromagnet (coil), an armature (movable contact), and a set of contacts (normally open or normally closed). The basic working principle of an EMR is quite simple： when a current passes through the coil, it generates a magnetic field that attracts the armature, thus opening or closing the contacts, which either completes or interrupts the circuit. In more detail, the relay typically has two types of contacts： Normally Open (NO) and Normally Closed (NC). Normally Open (NO)： These contacts remain open when the relay is not energized. When the relay is activated by applying a current to the coil, the contacts close, allowing current to pass through the circuit.