Different Types of Relays And Their Functionality

Relays are like the remote-control device that are responsible for putting an electronic circuit on the “ON” and “OFF” mode. The electromagnetic device is used in many applications because of their relative simplicity, long life, and most important proven high reliability.

Relays are used in a wide variety of applications throughout the industry, like telephone exchange, digital computers and automation system. Highly sophisticated relays are used to protect electric power system against all the resistance, trouble, and power blackout as well as to regulate and control the generation and distribution of power.

If we notice in our real-life surroundings, the relays work as an important function in the machines like the refrigerator, washing machine, dishwasher, and air-conditioning controls. Relays are associated with electric circuits and play an essential part in the overall functionality.

Functions of Relays:

The functions of relays have been categorized into three types:

• On/Off control

• Limit control

• Logic control.

All the functionality can be explained through a separate example. For On/Off functionality, we can see the AC conditioning control used to limit and control a high-power load such as a compressor.

Limit control works for Motor speed control that is used to disconnect a motor if it runs slower or faster than the desired speed.

The logic operation works with test equipment that connects the instrument to a number of testing points on the device under the test.

Types of Relays:

Relays are structured differently as per the functionality of a device required. Due to this, different kinds of relays exist and categorize to give a clear view to the manufacturers to select one as per their wish. Let us understand each type separately below:

Electromagnetic Relays:

Electromagnetic relays have electrical, mechanical, magnetic components, operating coil, and mechanical part as its main composition. When the power supply on with these systems, the cold gets activated, and mechanical contact starts functioning on open or close modes. The power supplies through the relay can be AC or DC.

Further electromagnetic relays divide on some of its common features:

Attraction type:

This kind of relays mainly work with AC and DC supply and attract a metal bar or a piece of metal when power is supplied to the coil. This can be a plunger being brawn towards the solenoid being attracted towards the pole of an electromagnetic.

Induction type:

Induction types electromagnetic relays used as the protective relays in AC systems alone and is usable with the DC system. The activated force for contacts movement is developed by a moving conductor that may be a disc or a cup, through the interaction of electromagnetic fluxes due to fault currents. Various shaded pole, watt-hour and induction cup structure and are mostly used as directional relays in power system protection and also for high-speed switching operation applications.

DC Relay:

It works on the principle of electromagnetic induction. The functionality of DC relays employed with a freewheeling diode to de-energize the cold.

AC Relays:

Like DC Relays, it follows the principle of electromagnetic induction. The very interesting aspect of an AC is that for every half cycle, the direction of the current supplied changes, for every circle coil loses its magnetism since the zero current in every half-cycle makes the relay continuously make and break the circuit.

Relays is an important component and available in different types of relays that are employed in most of the electronic as well as electronic circuits. The information given above can be quite helpful for the people who are looking for the relay for the better functionality of the machine.