What is a relay used for in electrical systems?

A relay plays a crucial role in electrical systems as an electrically operated switch, specifically designed to control high-power circuits. This means that it can enable or disable a circuit without requiring the operator to handle high current or voltage directly, ensuring safety and ease of operation. The relay uses a small input signal to control a larger output current, making it an essential component for automation and control in electrical systems.

In various applications, relays allow for remote controlling of devices, automation of circuits, and managing multiple circuits through a single control signal. This function is especially important where safety and operational efficiency are paramount, such as in industrial settings or complex electrical panels. Relays can also help in protecting sensitive electronic components by isolating them from high voltage/current operations.

Other options, such as a power supply, high-voltage breaker, or a device for storing electrical energy, do not accurately define the specific role of a relay within an electrical system. Each of those serves different primary functions, such as providing power, interrupting circuits during fault conditions, or storing energy for later use, respectively, but they do not embody the primary purpose of relays as active switches for controlling circuits.