What is the function of an electrical relay?

An electrical relay functions primarily as a switch that allows a low-power signal to control a high-power circuit. This capability is crucial in various applications where safety and efficiency are paramount. By using a small input current to energize a coil within the relay, the mechanical movement engages contacts that either open or close a larger circuit, enabling or disabling the flow of more substantial electricity without direct physical interaction with high-voltage components.

This design serves multiple purposes: it isolates the control side from the higher power side, enhances safety by minimizing the risk of electric shock, and allows for automation in control systems by utilizing low-power signals from sensors or microcontrollers. Such an arrangement is commonly found in automotive systems, industrial controls, and home automation, showcasing the versatility and essential nature of relays in electrical engineering.

The other choices refer to different electrical devices or functions. Increasing voltage levels pertains to transformers rather than relays, while storing energy pertains to capacitors or inductors. Converting AC to DC is typically the role of rectifiers, which are not the same as relays. Hence, the option of controlling a high-power circuit through a low-power signal stands out as the primary responsibility of an electrical relay.