Lesson 01

What is Relay

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Electronics Education

What is Relay (Relay Educational Visualizer)

A relay is an electrically operated switch that lets a low-power control signal switch a higher-power load while also providing electrical isolation.

Relay Type

SPDT

Coil State

OFF

Contact

NC

Load

OFF

Tests

PASS

Controls

Realtime Explanation

A relay is an electrically operated switch. With the coil off, COM stays on the NC side in the normal state.

Electromagnetic field: OFF

Interactive Relay Visualizer

DCpowersupplyCoilCoilNCNOCOMACLampACpowersupplyRelay OFF - Contact on NC - Lamp OFF

Relay Parts

Coil, armature, COM, NO, NC, flyback diode, and load connection are the main parts used in a relay circuit.

Why Flyback Diode?

When the coil turns off, it can create an inductive voltage spike. A flyback diode protects the transistor or driver from that spike.

Applications

AC lamp control, fan or motor switching, pump control, automation panels, and PLC outputs are all common relay applications.