What is the purpose of a relay in electrical systems?

A relay in electrical systems serves the essential purpose of controlling a high-power circuit using a low-power signal. This function is critical because it enables safe and effective management of electrical devices that require more power than what the control circuit can handle directly.

When a low-power control signal is applied to the relay, it activates an electromagnet that operates a switch, allowing a higher current to flow in another circuit. This action is pivotal in applications such as automated systems, where a small signal from a microcontroller can switch on or off larger devices like motors or lights without the risk of overloading the control circuit.

Understanding this function highlights the relay's role in enhancing safety and efficiency in electrical setups by isolating the control components from the high-power parts of the circuit, thus preventing damage and ensuring reliability.