At its core, a relay is an electrically operated switch. It consists of a coil, an armature, contacts, and a spring. When an electric current passes through the coil, it generates a magnetic field that pulls the armature, causing the contacts to either close or open, depending on the type of relay. This action allows the relay to control larger loads with a much smaller control signal. The primary function of a relay is to isolate different parts of a circuit while ensuring smooth operation.

    Relay circuits are commonly used in industrial automation, automotive applications, home appliances, and many other sectors. They provide a reliable method of controlling high-power devices, such as motors, lights, and heating elements, while ensuring the safety of low-power control circuits.