This relay-controlled car horn circuit employs a 4-pin relay to regulate the operation of an automobile horn. The relay is connected to the car's horn button and battery. When you press the horn button, it activates the relay, which closes the circuit for the car horn, causing it to sound. This configuration enables the horn to be engaged via a low-power signal from the horn button, while the high-power current required by the horn is supplied straight from the automobile battery.
