A relay works on the simple principle of using a small electrical signal to control a larger electrical circuit. It acts as an electrically operated switch that allows one circuit to control another, making it essential in automation, control panels, and protection systems. Omron relays are among the most widely used in industries because of their high reliability, precision, and long service life.
The working principle of a relay is based on electromagnetic induction. When a small current flows through the relay’s input coil, it creates a magnetic field around the coil. This magnetic field attracts a movable metal armature that is mechanically linked to one or more sets of contacts. When the armature moves, it either closes or opens the contact points. This action switches the output circuit ON or OFF, depending on the relay design. In simple terms, when the coil is energized, the magnetic field pulls the contacts together (in a normally open relay) to complete the circuit. When the current stops, the magnetic field disappears, and the spring returns the contacts to their original position, turning the circuit OFF.
Relays come in two main contact configurations — Normally Open (NO) and Normally Closed (NC). In a Normally Open relay, the output circuit stays open until the coil is energized. In a Normally Closed relay, the output circuit remains closed until the coil is powered, and it opens when current flows. This makes relays versatile for both switching and protection applications.
Omron relays are designed to perform this switching function efficiently across different voltage and current ranges. They are available in various types, including electromechanical relays, solid-state relays (SSR), and time-delay relays. Electromechanical relays use a physical armature to open or close contacts, while solid-state relays perform the same function using semiconductor components for faster and silent operation.
In industrial systems, relays are used to control motors, heaters, lamps, alarms, and other high-power devices safely through low-power control signals from PLCs or sensors.
In simple words, a Relay works by using an electromagnetic coil to open or close electrical contacts, allowing a small control signal to switch a much larger load. Omron relays perform this function with high accuracy and durability, making them ideal for both industrial and automation applications.