How A 12 Volt Relay Works

3 pin 4 pin 5 pin iso standardized relays iso relays were designed to try and standardize relay connections making it easier to test and design systems.

How a 12 volt relay works.

In electromechanical relays emr contacts are opened or closed by a magnetic force. What happens inside a relay isn t magic but it is important. Here s another video explaining the what s how s and why s about our friend the relay. 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.

Gday guys and gals. Applying a small amount as low as 2 amps of current to the relay coil closes contacts to feed power to an accessory that requires more current to operate usually over 20 amps. 5 pin relay 5 pin relays provide 2 pins 85 86 to control the coil and 3 pins 30 87 87a which switch power between two circuits. When the relay is energized on pins 3 and 5 have continuity.

To wire an automotive relay make at least four connections. I firstly describe how the rela. Relays are either electromechanical relays or solid state relays. In this video i give you a thorough look at how a 12v automotive relay works and also how to wire one up.

A normally closed relay will switch power off for a circuit when the coil is activated. Understanding how the relay works will help with diagnosis and modifications to vehicle systems. The decision to use electromechanical or solid state relays depends on an application s electrical requirements cost constraints and life expectancy. A normally open relay will switch power on for a circuit when the coil is activated.

A relay is essentially a switch that is operated electrically rather than mechanically. With solid state relays ssr there are no contacts and switching is totally electronic. Two wires to the. What is a relay.

Most 12 volt relays operate accessories in a motor vehicle.