Definition - What does Relay mean?
Relay is an electrical switch used to control an electrical circuit. The first relays were used only in telegraph circuit as amplifiers but nowadays they are also used in telephone exchanges or computers to execute logical operations. There are multiple types of relays and some can handle high power voltage when fitted in an electric motor. Relays that protect circuits from overload are called protective relays. A simple relay has a coil wrapped with a wire that offers low reluctance path for magnetic flux.
Petropedia explains Relay
A Relay acts as a remote control switch in a circuit to maintain the flow of the current. It has a broad range of applications due to its high reliability, simplicity, and long life. It is mostly used in:
- Telephone exchanges
- Digital computers
- Automation systems
- Electric power systems
The basic functions of a relay are to control the on/off switch, logical operations and restrict the limits. As there are a number of relays thus one can choose as per their needs and requirements. Some of the commonly used relays are mercury relay, latching relay, reed relay, polarized relay, coaxial relay, etc.