EngrEDU_Repository

Brief Introduction
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The conceptual operation of an electromechanical relay is presented below. Briefly, it has two parts, a coil on one side (primary circuit) and a switch on the other side (secondary circuit). When the coil is energized (red color) it creates a magnetic field that attracts the switch. When there is no energize (black color) on the coil, the switch goes back to it's initial position.

schematic_relay.gif

You can see a transparent relay working below. Pretty cool 🙂

physical_relay.gif

Functions of Relays
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  • Galvanic separation of the primary circuit (actuator) and secondary circuit (load)
  • Separation of different load circuits for different types of secondary circuits (different types of switches)
  • Separation of AC and DC circuits
  • Interface between electronic and power circuits
  • Multiple switch operations (e.g.: time delays, signal condition)

relay_schematic_example.png

According to the schematic above, this electromechanical relay will have a total of 5 pins. 2 pins for the control side (the coil) and 3 pins for the other side (the switch). However relays might have more or less pins depending on the type of switch used.

Table Of Contents

Brief Introduction

Functions of Relays