A miniature relay is essentially a small mechanical switch that opens or closes a circuit when an electrical signal is applied to its coil. It consists of a coil, an armature, a set of contacts, and a spring. When a current flows through the coil, it generates a magnetic field, causing the armature to move and either open or close the contacts, depending on the design of the relay. This action allows the relay to control higher current circuits using a low-power signal.

    Due to their small size, miniature relays are often used where space is a concern but reliable switching is still required. They are available in a variety of configurations, including single-pole single-throw (SPST), single-pole double-throw (SPDT), and multiple-pole variations, providing flexibility in circuit design.