What is the function of a relay in electrical circuits?

In electrical circuits, a relay serves the crucial function of using a small electrical signal to control a larger current flow. It acts as an electrically operated switch that enables a low-power signal to control a high-power circuit. This is achieved through an electromagnetic coil that, when energized, creates a magnetic field which actuates a switch mechanism.

The significance of this function lies in the ability to control heavy loads safely and effectively without directly exposing switch components to high current levels. By using a relay, it is possible to manage the power flow in various applications, from simple lighting controls to complex machinery, all while ensuring that the control circuitry remains low-power and protected from the high voltages and currents present in the operations being controlled.

Other options do not describe the primary role of a relay. Increasing voltage levels pertains to transformers or similar devices, converting AC to DC involves rectifiers and not relays, while providing a direct current path is more aligned with connectors or wiring rather than the distinct function of a relay, which focuses on control of larger currents through the action of a small signal.