What is a Relay in Electrical Working: Understanding the Connection Diagram
Relays are electrically operated switches that can be used to control high voltage and high current circuits. They are an essential component in electrical systems, allowing signals to be transmitted from one circuit to another, or to switch on and off various electrical loads.
A relay is a switch that opens and closes based on an electrical signal. It is a crucial component in electrical systems as it can help regulate the flow of electricity and protect electrical circuits from damage. In this article, we will take a detailed look at the working of a relay, its connection diagram and the various types of relays available in the market.
How does a Relay work?
A relay works by using an electromagnet to control the switching of a high voltage or high current circuit. The electromagnet is activated by a small electrical current that flows through the coil. This creates a magnetic field that pulls the armature towards the electromagnet, closing the contacts and allowing electrical current to flow through the relay.
When the current flowing through the coil is stopped, the magnetic field collapses and the armature returns to its original position, opening the contacts and stopping the flow of current. This mechanism allows the relay to switch on and off the high voltage or high current circuit, based on the control signal applied to the coil.
Relay Connection Diagram
The connection diagram of a relay can be quite complex, but the basic components include the coil, the armature, the contacts and the power supply. The power supply provides the electrical energy required to activate the electromagnet.
In a typical relay circuit, the coil is connected in series with a switch and a power source. When the switch is closed, electrical current flows through the coil, creating the magnetic field and activating the relay.
The armature is connected to the contacts, which are the electrical switch that opens and closes based on the position of the armature. The contacts are connected to the high voltage or high current circuit that needs to be controlled by the relay.
Types of Relays
There are various types of relays available in the market, each with their own unique features and specifications. Some of the most commonly used relays are:
- Electromagnetic Relays
- Solid State Relays
- Reed Relays
- Latching Relays
Electromagnetic relays are the most commonly used type of relay, and they work by using an electromagnet to control the switching of the contacts.
Solid state relays, on the other hand, use semiconductors to switch the high voltage or high current circuit.
Reed relays are small and lightweight, making them ideal for use in portable devices.
Latching relays are used when a relay needs to remain in a specific state, even after the control signal is removed.
Relay Operating Principle:
All electromagnetic relays are working based on Faraday’s Electromagnetic Induction. For instance, if we close the external circuit contact, the current start flows from power source to coil.
Then the coil becomes electromagnet and which attracts the iron core placed inside the coil. Also, the iron core pulls the relay contact terminal A. Due to this, A and B will be connected.
Then the current starts flowing in the external control circuit. Finally, the Lamp blows.
Conclusion:
relays play a crucial role in electrical systems, allowing signals to be transmitted from one circuit to another, or to switch on and off various electrical loads. Understanding the working of a relay, its connection diagram and the various types of relays available in the market can help in making informed decisions when designing and implementing electrical systems.
