What is the function of a relay in an electrical system?

The function of a relay in an electrical system is to serve as an electrically operated switch that controls a circuit. This mechanism allows a low-power signal to control a larger power circuit, enabling the activation of devices such as motors, lights, or other electrical components. Relays operate by using an electromagnetic coil that, when energized, creates a magnetic field to physically move a switch mechanism. This functionality is particularly useful in automation and control systems where multiple devices need to be turned on or off based on a specific condition or signal without direct manual intervention.

By using a relay, it provides a means to isolate different parts of a system, where the circuit that controls the relay can be kept separate from the high-power circuit that it governs, which enhances safety and circuit protection. This property makes relays indispensable in many applications, such as automotive systems, industrial controls, and home automation.