NSN Catalogue Blogs

In an electric circuit, a relay is a component used to switch electrical contacts. Specifically, a relay is an electromagnet containing an internal spring-loaded lever. The spring, or coil, energizes the relay by conducting either an alternating current (AC) or direct current (DC) around the core. This small current in turn magnetizes the core which attracts the lever to switch a large electrical current between contacts. The initial current can be sourced from a few places, those of which include another switch, the circuit board the relay is on, or another electrical circuit. To further understand the applications of a relay, this blog will explore the difference between alternating current and direct current as they function to control current through a relay coil.