How Does A 12 Volt Relay Work

Second relay coil 5v i want the system to start the 12 volt battery automatically when power goes off.

How does a 12 volt relay work.

A datasheet is a document with detailed specifications of a component. So how much voltage does a 12v relay need to work. Although there are various relay designs the ones most commonly found in low voltage auto and marine applications are electro mechanical relays that work by activating an electromagnet to pull a set of contacts to make or break a circuit. However the real benefit behind a relay is more than just automation.

A relay is essentially a switch that is operated electrically rather than mechanically. The purpose of an automotive relay is to automate this power to switch electrical circuits on and off at particular times. They also provide the ability to switch multiple circuits including different voltage types within. Understanding how the relay works will help with diagnosis and modifications to vehicle systems.

Let s start by looking at a datasheet for an ad pr40 1c 12d 12v relay which is an open style power relay. What happens inside a relay isn t magic but it is important. Relays in general are used to enable a low amperage circuit to switch on or off a higher amperage circuit like turning on your headlights.