Relay current refers to the amount of current that flows through the coil of a relay when it is activated. This current is responsible for creating the electromagnetic field that causes the relay’s switch to either open or close, depending on the design of the relay. The relay coil is usually connected to a low-power circuit, and when current flows through it, it generates a magnetic field that moves the relay's armature. This armature, in turn, opens or closes the contacts, allowing a larger current to flow through the connected circuit.

    This current is often referred to as the "excitation current" because it excites the relay's electromagnetic mechanism, triggering the relay to perform its intended function. The strength of the magnetic field generated depends on the magnitude of the relay current, which in turn determines the performance and reliability of the relay.