This relay control circuit utilizes a 3-pin relay with a coil, a DC source connected through a switch, and a neon lamp. The relay coil is energized by the DC source when the switch is closed, causing the relay contacts to close and complete the circuit for the neon lamp, which is also connected to one end of an AC 220V supply. This setup allows the low-voltage DC circuit to control the high-voltage AC circuit, demonstrating the fundamental principle of relay operation.
