---
title: Relays
tags: [electronics]
created: Monday, September 09, 2024
---

# Relays

A relay is an electrically operated switch.

It uses an electromagnet to mechancially operate a switch.

## Core components

- electromagnet
  - a coil of wire around an iron core
- armature
  - a movable magnetic strip
- contacts
  - electrical connections that can be open or closed
- spring
  - returns the armature to its resting position when not energised

## Operation

![Operation of a relay](../img/relay.gif)

Current flows through the electromagnet which creates a magnetic field. This
field attracts the armature which then moves to open or close the contacts. When
the current stops, this returns the armature to its original position.