An electromagnetic relay is an electrically operated switch that is used to control an electrical circuit by means of an electromagnet. The electromagnet is energized by an electrical current, which causes a mechanical armature to move and make or break an electrical connection. Electromagnetic relays are used in a wide variety of applications, including control systems, telecommunications, and power distribution.
There are several types of electromagnetic relays, including:
- Normally open (NO) relay: This type of relay has a set of normally open contacts that close when the electromagnet is energized.
- Normally closed (NC) relay: This type of relay has a set of normally closed contacts that open when the electromagnet is energized.
- Changeover (CO) relay: This type of relay has a set of normally open contacts and a set of normally closed contacts. When the electromagnet is energized, the normally open contacts close and the normally closed contacts open.
- Latching relay: This type of relay has a set of contacts that remain in the same state after the electromagnet is de-energized.
- Time-delay relay: This type of relay has a built-in timer that controls the duration of the electrical connection.
- Overload relay: This type of relay is used to protect an electrical circuit from overloading. It is designed to open the circuit when the current exceeds a certain level.
In conclusion, the electromagnetic relay is a widely used component in electrical and electronic systems, and its types are used to control, switch and protect electrical circuits in various ways.