Definition

Noun: 1. A switching device: An electrical relay is a component that uses a small electrical signal to control a much larger electrical signal in a separate circuit. It acts as an electrically operated switch.

Usage

An electrical relay is used to isolate and protect control circuits, to allow a low-power circuit to safely control a high-power circuit, or to control multiple circuits with one signal. * The thermostat uses an electrical relay to turn the furnace on and off. * A small current from the computer's output pin activates the electrical relay, which then supplies power to the motor.

Advanced Usage

• "To relay a signal": While the verb "to relay" means to pass something on, in an engineering context, it specifically describes the function of an electrical relay receiving and retransmitting a control signal.
  • The module relays the command from the sensor to the main power unit.

Variants and Related Words

• Relay (noun): The common shortened form of "electrical relay."
  • Check the relay in the fuse box.
• Latching Relay: A type of relay that maintains its state after being pulsed.
• Solid-State Relay (SSR): A relay that uses semiconductor components instead of mechanical parts to perform switching.

Synonyms

• Switch (specifically an electrically actuated switch)
• Contactor (a type of high-power relay)

Related Phrases

• Relay coil: The electromagnet inside the relay that is energized by the control signal.
• Relay contacts: The physical switch terminals that open or close the controlled circuit.

Noun

1. electrical device such that current flowing through it in one circuit can switch on and off a current in a second circuit