Auto Electrical Relays Explained – How they work and where they’re used.

Auto Electrical Relays Explained – How they work and where they’re used.


In this video we’re going to look at auto
electrical relays, how they work, and where they are used. Relays are switches that are turned
on or off by a small electrical current. These can have many uses in vehicles, a popular use is the switching of high power circuits such as spot lights. At the heart of the relay is an electro magnet. When a small current energises this electro-magnet, it attracts an armature blade and
closes contact points. Current that the relay is designed to switch
on or off can then flow across the contacts to the high power circuit. As long as the small switching current flows to the relay, the much larger current will
flow through its contact points. A more advanced type of relay is a double
throw Also Known As a change over relay. This relay has 2 outputs, one of which is normally
open and the other is normally closed. In the rest position the normally closed contacts
allow current to flow from the source to the circuit. When the electro magnet is energised, it attracts the armature, breaking the current to the
Normally closed contacts and closing the contacts for the Normally open side of the relay. The application for this type of relay can vary but is most commonly found in car headlights
to switch from low to high beam.

About the Author: Michael Flood

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