Wed. Jul 24th, 2024

Many of us are familiar with the name relay.  Relay is an electromechanical device that works as a switch through electromagnetic, spring, armature, and contact points. 

The relay was invented by U.S Scientist Joseph Henry. In the beginning, relays were used to transfer Morse Code signals to long-distance but now there are various features and applications of a Relay switch.

 The interesting thing about relays is that it works as both ON/OFF switch. Relays can use from very small electronic circuits to large ones of high voltage. A relay is also known as an auxiliary miniature or control relay. 

1. Relays in Electric Circuits: 

Relays are used in Electric Circuits for protection purposes. They can sense faults in the circuit breakers. As soon as the circuit breaker gets the signal it breaks the circuit. They are mostly used in substations and power distribution centers because they sense different faults in circuit breakers. To replace your circuit breakers with the latest electrical panels, you can search the web for Control Panel builder near me.

2. Industrial Automation System: 

In Industrial Automation Systems the relays are highly used for process controls. These are considered the backbone in this field because they are used with a combination of PLCs. Automation cabinets consider relays as their key component. 

3. Smart Control of Traffic Signals: 

SPST relays are becoming very famous in the field of controlling traffic signals. These relays help collect data from vibrating sensors. They can control red, yellow, and green signals. Other than that railway stations also use it for signalling purposes. 

4. Temperature-Based Control of Table Fan: 

SPDT relays are very often used to control the speed of DC motors or fans. PWM signals are used in this regard. The SPDT relay provides resistance depending on the temperature which leads the fans at different speeds. 

Other than that, the AC equivalents are done by using power resisters and semiconductor devices. For instance, usually, a power resister can resist 120 ohms to 60 ohms. An SPDT relay is designed to provide resistance up to 120 ohms. 

5. Applications of Relay in Electronic Circuits: 

Relays are used in electronic circuits rather than electrical circuits. It is quite astonishing to know that the electronic circuits of these relays are used for amplifying purposes. This is because these relays can switch a high amount of current to take a much lesser amount. 

Other applications of relays in electronic circuits include use in motor control circuits, logical control circuits, and PLC (programmable logic controller). They are famous for their use of microcontrollers to drive large loads. 


In sum, Relays are almost part of every other electronic device we see around whether it is in our household appliances or industrial relays are always tremendous at their work. With time the relays have enhanced application levels and have transitioned from only telegraph lines to a lot more than that. 

Some of the most common applications of relays include relays in electric circuits, industrial automation systems, traffic signals, table fans, and AC and electronic circuits.