Relay Contact Types
As Relay is a switch, so the terminology of ‘Poles & Throws’ is also applicable for relay. Relays are classified depending on the poles and throws
- Single Pole Single Throw Relay (SPST): It consists of only one pole one throw which path is easier of closed or opened. The best example for this is a Push Button. It is used for the applications which is require the ON or OFF state.
- Single Pole Double Throw Relay (SPDT): It consists of only one pole but has two throws. The example for this is a Slide switch. It is also called as changeover relay.
- Double Pole Single Throw Relay (DPST): It consists two poles and a throw. It can be used to connect two terminals of a single circuit at a time. Toggle Switch works on this property.
- Double Pole Double Throw Relay (DPDT): It consists two poles but the individual pole has two throws. These are used for phase or polarity reversal in motor direction control.
DIAGRAM
What is Relay?
A relay is an electrically operated switch in the context of electronics and electrical engineering. It is made up of a coil and one or more contact sets. When an electrical current runs through the coil, a magnetic field is created that activates the contacts, allowing them to open or close the circuits. Relays are frequently employed in automotive applications, industrial automation, and control systems to control high-power or high-voltage devices with a lower-power signal.
Table of Content
- Electrical Relay Definition
- Electrical Relay Structure and Operating Principles
- Contact Types of Relay
- Electrical Relay Types and Classification
- Applications of Relay
- How to Test a Relay?
- Advantages and Disadvantages of Relay