Relay current refers to the electrical current flowing through a relay coil to energize it and activate its corresponding switch mechanism. Relays are electromechanical devices that use an electromagnet to open or close contacts, allowing a controlled flow of electricity in a circuit. The current required to activate the relay depends on the coil's design and the voltage applied to it. When the relay coil is energized, it creates a magnetic field that moves the switch, which in turn either completes or interrupts the circuit.

    Relays are used extensively in situations where high current needs to be controlled by a low current circuit, offering the advantage of isolating different parts of a system. This is particularly useful in sensitive electronic systems, where it is critical to prevent high-power circuits from affecting the more delicate components of the system.