What is a 12V Relay

A 12V relay is a switch that is electrically operated instead of mechanically. Although there are various relay designs, the most commonly used relays are in cars. However, you will also find them in light trucks and low-voltage ships.

Electromechanical relays work by activating an electromagnet to attract a set of contacts to make or break a circuit. They are mainly used for activating horns, headlights, and fan motors. A 4-pin 12V relay connects via a switch to both the positive and negative sides of the vehicle's power source, ensuring efficient power regulation.

Relais 12v

How does a 12V relay work

Relays are installed between the power source and the electrical accessory that requires on/off power. When the relay is energized, the high current flows from the power source through the relay and directly to the component to operate the accessory.

When do you use a 12V relay

Relays are crucial when it comes to operating a circuit with a low power signal, where complete electrical isolation between the controlling and controlled circuits must be ensured. Additionally, relays are used to manage multiple circuits with just a single signal.

Connecting a 4-pin 12V relay

A 4-pin relay offers much flexibility and control options compared to other types of relays. These relays have four terminals that can be configured in various combinations of open and closed states, such as two open and two closed, three open and one closed, or all four open.

Pin numberConnectiondescription
86Control current inputThe pin where the control voltage enters the relay, used to activate the coil.
85Output control currentThe return pin for the coil, usually connected to ground.
30Ingang hoofdstroomThe common power input for the relay, the source of the main current.
87Uitgang hoofdstroomThe output where the main current leaves the relay when activated, to the switched device.

This versatility enables the control of complex circuits and adaptation to specific system requirements, such as managing multiple circuits with different current requirements simultaneously. 4-pin 12v relays use 2 pins (85 & 86) to control the coil and 2 pins (30 & 87) that switch the current in one circuit.

There are 2 types of 4-pin relays available; normally open or normally closed. A normally open relay switches the voltage ON for a circuit when the coil is activated. A normally closed relay switches the voltage OFF for a circuit when the coil is activated.

12v relais closed

Connecting a 3-pin 12v relay

A 3-pin relay has three connections and is more limited in configuration, often only capable of functioning in a normally open state. This means that the current only passes through the relay when it is activated. Such relays are simpler and are often used for basic on/off switching tasks where no complex switching or multiple output configurations are required.

Canbus proof i-LS Relay

For the automotive industry, we recommend the i-LS Relays from Led Autolamps. The built-in microprocessor prevents unreliable error signals from being generated by indicator lights. This can be caused by the extremely low current consumption of LED lamps when installed on traditional incandescent lighting systems.

The i-LS relay is designed to be used in conjunction with our i-LS microprocessor, enabling the reliable detection of a fault in an LED indicator.

The system warns the driver when an indicator is faulty by speeding up the turn signal or by turning off an indicator light on the dashboard.

Schema I-LS Relay

Video: 12V Planet