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Electrical & Electronics Engineering vocabulary · Circuits and Components

Relay

Meaning in electrical & electronics engineering, with examples

/ˈrileɪ/nounCore term

In electrical & electronics engineering, relay means: An electrically operated switch: a small current through its coil moves contacts that switch a separate, often much larger circuit. Solid-state relays do the same job without moving parts.

In Turkish: röle

How it is used

Used in control panels, vehicles and electronics. A relay is energized or de-energized, its contacts open or close, and you can hear it click. Engineers talk about the coil voltage, the contact rating and NO/NC contacts.

Example sentences

  1. You can hear the relay click, but the pump still doesn't start.

  2. The relay coil is 24 V DC and the contacts are rated for 10 A at 250 V AC.

Common collocations

  • relay coil
  • relay contacts
  • solid-state relay
  • energize a relay
  • safety relay
  • switchA device that opens or closes a circuit, either by hand or automatically. It can be mechanical, like a toggle switch or a push button, or electronic, like a transistor.
  • transistorA semiconductor device used to switch or amplify signals. A small current or voltage at one terminal controls a much larger current through the other two.
  • diodeA semiconductor component that lets current flow easily in one direction and blocks it in the other. Its two terminals are called the anode and the cathode.
  • motorA machine that converts electrical energy into mechanical rotation. Most industrial machines use three-phase induction motors, while small devices often use DC or brushless motors.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Circuits and Components

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