A 12V relay is essentially an electromechanical switch that is controlled by a low-voltage electrical signal. It consists of a coil, contacts, and an armature. When a 12V DC voltage is applied to the coil, it generates a magnetic field that pulls the armature, which then opens or closes the contacts, depending on the design of the relay. The contacts can either be normally open (NO) or normally closed (NC), with the state changing when the relay is energized.

    The primary function of a relay is to isolate different parts of a circuit. A small voltage on the control side (the 12V DC side) can control a larger voltage or current on the switched side. This makes the 12V relay crucial for applications where low voltage microcontrollers or logic systems need to control high-power equipment.