At its core, a relay is an electromagnetic switch that uses an input signal, typically a low-voltage current, to control a larger current in another circuit. When the input signal is applied to the relay’s coil, it creates a magnetic field that moves a metallic armature, thereby opening or closing the contacts. This action not only enables the control of high-voltage circuits but also ensures electrical isolation between the control circuit and the load circuit.

    The Working Principle of Relay Signals

    The working principle of relay signals is quite straightforward. When a voltage is applied to the relay coil, the coil becomes magnetized, pulling the armature towards it and causing the switch contacts to change state. This can either complete a circuit (close the contacts) or break the circuit (open the contacts). The mechanical movement involved in this process is key to the relay’s ability to control much larger loads without direct electrical connection. The actuated contacts safely manipulate significant currents and voltages, significantly amplifying the control capabilities of a small input signal.