The meaning of RELAY is a supply (as of horses) arranged beforehand for successive relief. How to use relay in a sentence. To summarize, a relay is a simple electromechanical device used to control electrical circuits by opening and closing contacts in response to an external signal. When an electrical current runs through the coil, a magnetic field is created that activates the contacts, allowing them to open or close the circuits. Relays are frequently employed in automotive applications, industrial automation, and control systems to control high-power or high-voltage devices with a lower-power signal. How to Test a Relay? A relay is an electrically operated switch that uses an electromagnet to mechanically operate a set of contacts. It is widely used in circuits to control a high-power or high-voltage circuit with a low-power signal, providing isolation between the control and load circuits.
