14 – Relay

The picture shows a sketch of a Relay on the left and the symbol on the right.

A relay is an electronic\electric component that is used to operate a switch electrically. The relay consists of two components an electromagnet and the electrical contacts that can be closed or opened when the electromagnet is activated. There are various types of relays too many to mention, from low current to high voltage with a varying number of switching contacts and configurations. Normally a control circuit will connect the coil of the relay to the supply voltage this will activate the electromagnet and the relay will then switch on, making or breaking contacts depending on the configuration.

Relay’s are used in almost every thinkable application the following is just few application examples:

  1. Switching on large amounts of power with a small electronic signal.
  2. Switching on AC powered equipment with a low power digital signal.
  3. Connecting or disconnecting equipment remotely.