A 12v relay is an electronic device that allows you to control a high-power circuit with a low-power signal. This makes it an ideal choice for many different applications, such as automotive, industrial, and home automation. In this article, we’ll take a closer look at how a 12v DC relay works, and provide you with a detailed wiring diagram that you can use to hook up your own relay in no time.
What is a 12v DC Relay?
A 12v DC relay is an electrical switch that is activated by a low-voltage signal. When the signal is applied to the relay coil, it creates a magnetic field that pulls a set of contacts together, allowing current to flow through the circuit. When the signal is removed, the contacts return to their original position, breaking the circuit.
Relays come in many different sizes and shapes, ranging from tiny solid-state relays that can be mounted on a circuit board, to large electromechanical relays that can handle hundreds of amps of current. However, the basic principle remains the same regardless of the type of relay that you are using.
How Does a 12v DC Relay Work?
A typical 12v DC relay consists of three main components: the coil, the contacts, and the contact springs. The coil is made of copper wire and is wound around a metal core. When current flows through the coil, it creates a magnetic field that pulls the contacts together. The contacts are made of metal and are connected to the circuit that you want to control. The contact springs are used to hold the contacts in place and to ensure that they open and close smoothly.
When the signal is applied to the relay coil, the magnetic field created by the coil pulls the contacts together, allowing current to flow through the circuit. When the signal is removed, the contact springs return the contacts to their original position, breaking the circuit.
12v DC Relay Wiring Diagram
Now that you know how a 12v DC relay works, let’s take a look at a wiring diagram that you can use to hook up your own relay. In this diagram, we’ll be using a 5-pin relay with a normally open configuration, which means that the contacts are normally open until the relay is activated.
| Pin Number | Function | Wire Color |
|---|---|---|
| 1 | Coil Positive | Red |
| 2 | Coil Negative | Black |
| 3 | Normally Open Contact | Blue |
| 4 | Common Contact | Yellow |
| 5 | Normally Closed Contact | Green |
To wire up the relay, you’ll need to connect the coil to a 12v power source, such as your car battery or a power supply. The normally open contact will be used to control the circuit that you want to turn on, while the common contact will be connected to the power source. The normally closed contact can be left unconnected or used to control another circuit if needed.
Step 1: Connect the Coil
The first step is to connect the coil to a 12v power source. To do this, connect the red wire from the relay to the positive terminal of your power source, and connect the black wire to the negative terminal. This will provide power to the coil and allow it to be activated when the signal is applied.
Step 2: Connect the Normally Open Contact
The next step is to connect the normally open contact to the circuit that you want to control. To do this, connect the blue wire from the relay to the input of your circuit, such as the positive input of a light or motor. When the signal is applied, the contact will close, allowing current to flow through the circuit and turn on the device.
Step 3: Connect the Common Contact
The common contact is used to provide power to the circuit that you want to control. To connect it, connect the yellow wire from the relay to the positive terminal of your power source, such as your car battery or power supply. This will ensure that the circuit has power when the relay is activated.
Step 4: Test the Circuit
Once you have connected all of the wires, it’s time to test the circuit to make sure that it’s working properly. To do this, apply a signal to the coil by connecting a 12v power source to the red and black wires. The contact should close, allowing current to flow through the circuit and turning on the device that you are controlling. If everything is working properly, you’re done!
FAQs
What is a 12v DC Relay Used For?
A 12v DC relay is used to control a high-power circuit with a low-power signal. This makes it an ideal choice for many different applications, such as automotive, industrial, and home automation. Some common uses for relays include turning on lights, motors, and other devices, as well as providing power to other circuits.
How Do I Choose the Right Relay?
When choosing a relay, there are several factors that you should consider, including the type of circuit that you are controlling, the amount of current that the circuit requires, and the voltage of the circuit. You should also consider the mounting options and size of the relay, as well as any special features that you may need.
Can I Use a 12v DC Relay with AC Power?
No, you should not use a 12v DC relay with AC power. DC and AC power work differently, and using a relay that is designed for DC with AC power can cause damage to the relay or other components in your circuit. If you need to control an AC circuit, you should use a relay that is designed for AC power.
What Happens if I Connect the Wires Incorrectly?
If you connect the wires incorrectly, you can damage the relay or other components in your circuit. Always double-check your wiring before applying power to your circuit, and make sure that you have connected everything correctly. If you’re not sure which wire goes where, consult a wiring diagram or seek professional help.
Can I Control Multiple Circuits with One Relay?
Yes, you can control multiple circuits with one relay by connecting the normally open contact to the input of each circuit. However, you should make sure that the relay is rated for the total amount of current that the circuits require, and that the circuits are compatible with each other.
Conclusion
A 12v DC relay is a versatile and powerful electronic device that can be used to control a variety of circuits. Wiring up a relay is easy, and with the help of this article and our wiring diagram, you should be able to do it in no time. Whether you’re building an automotive project, an industrial machine, or a home automation system, a 12v DC relay is an essential tool that you should have in your toolbox.
