What is the function of a relay?

A relay serves as an electromechanical switch that controls the opening or closing of a circuit in response to an electric current. This mechanism is critical in various applications, allowing low-power control signals to manage higher power circuits safely and effectively. When an electric current flows through the relay's coil, it generates a magnetic field that moves an armature, either making or breaking a connection within the circuit.

This functionality is particularly valuable in automation and control systems, where it allows one circuit to control another without direct electrical connection, enhancing safety and efficiency. It can also be used in signal routing, protecting sensitive electronic components from high voltages or currents.

In contrast, amplifying electrical signals is the role of other components like transistors; storing energy in a magnetic field is typically associated with inductors or capacitors, not relays; and measuring electric potential is conducted by instruments such as voltmeters, rather than by relays. Understanding these distinctions highlights the specific role and importance of relays in electrical systems.