Key role of Relays in industries?

Key role of relays

Key role of relays

The key role of Relays

The Relays are nothing but switches. These are used electronically to close and open the circuits. It will control the electronic circuit. If the relay contacts open, then the relay is not stimulated with the open contact. If the relay contact closed, then the relay is not energize given the closed contact. The states are changed when the energy is supplied.

The relays are overload, overcurrent, undercurrent, and reverse current to the protection of electronic equipment. For heating of elements, relays are been used.

Types of Relays

  • The electromechanical and electromagnetic relay, a wide variety of relays with different principles.
  • The electrothermal relays are solid-state Relay, hybrid Relay.

The bimetallic strip is formed when the 2 different materials are contacted. then it will bend. Based on this bending the users make contact connections.

Types of Relays as per the Polarity

These are identical relays. It is applicable for telegraphical purposes. at our house, in TV remotes, press one button then the function will be generated. Actually, the relays are removed from the direct link of users to electronic equipment. Because to protect the user from high voltages. , for the motors and pumps operation, the bigger capacity relays are used in large industries. another example is, in a car dashboard, a headlight switching button, if it is moved, they supply the small value of current to the coil.

The common examples of relays in our daily life are, the mostly using in the houses are fridge, it is responsible for working and production of cold temperature. and in traffic lights, relays are used. and also the relays are utilized in the garage doors.

Relays are responsible for electronic equipment and their functioning. Here are no risks factors involved the high voltage as there will be no contact at the time of an electronic breakdown.

Applications of Relays

Relays are used in so many machines and devices that are used electrically.

  • Home electrical appliances
    • Refrigerators
    • Washing machines


  • Industrial machinery
    • Molding equipment
    • Industrial robots
    • Packing machinery
    • Programmable controllers


  • Plants
    • Chemical plants
    • Shale gas plants
    • Control panels for building management
    • Power stations control panels and transformer substations


  • Scientific equipment
    • Constant temperature tanks


  • Automatic vending machines and entertainment equipment
    • Vending machines
    • Amusement machines


  • Communications and measurement equipment
    • Measurement equipment


  • OA devices
    • Copy machines


General-purpose relays

In industrial automation systems, high-quality general purpose relays are used. Signaling and protection systems, control, and electric drive systems are the controlling applications. Building automation is a common controlling application.

The features of general-purpose relays are, 

In Relay functioning, there is an iron core determine with the control coin. The power connect with the electromagnet through a control switch. The upper contact arms attracted by the lower arm which closes the contacts. Spring and gravity are the reasons behind this force.

The relays performing the functions include high voltage application and low voltage application. In low voltage applications, the circuit noise is reduced. in high voltage, noise is increased.

The terms involved in Relay are

Seeled Relays

The Relays are enclosed and sealed in a container it is called seeled relays. some times seeled relays are called enclosed relays. These are closed without using any welding methods.

Hinged relays

Hinged relays are the structure of the electromagnet. these are directly or indirectly switch contacts by the rotating movement.

Plunger relays

These are the structure of the electromagnet. The configuration in a plunger relay is at the center of the coil and it moves to the coil axis.

DC and AC Relays

DC and AC inputs are operated to design with Relays.

Polarized Relays 

DC relays depending on the polarity of the input current that changes the status.


Applications of Electromechanical Relay

An Electromechanical Relay having magnetic, electrical, and mechanical components.

It has three terminals. They are, normally closed(NC) and normally opened (NO). which are opened or closed based on the operation. Utmost of the electromechanical relays are either attracted type or induction type. All relays are based on the working principle of electromagnetic attraction.

Electromechanical relay operations are Under Energized conditions and under De-energized conditions.

Functions of Relays are,

  • To serve as a switch where circuits need to be controlled
  • Some relays use an electromagnet to close and open contacts
  • Switching electric motors and lighting loads
  • save electrical circuits from overload, serving as protective relays.
  • Some relays use an electromagnet to close and open contacts