Fans are an essential component in electronic devices to keep the temperature under control. A 3-wire fan is a type of fan with three wires, namely the ground wire, the power wire, and the tachometer wire. In this article, we will discuss the wiring diagram of a 3-wire fan, its working principle, and frequently asked questions.
Working Principle of a 3-Wire Fan
A 3-wire fan is a DC fan that has a built-in controller to adjust the speed of the fan. The fan receives power through the power wire and uses the ground wire for the return path. The tachometer wire provides the fan’s speed feedback to the motherboard or fan controller.
The controller in a 3-wire fan utilizes a pulse width modulation (PWM) signal to regulate the fan’s voltage and speed. The PWM signal is a digital signal that controls the power delivered to the fan. The controller in a 3-wire fan uses the PWM signal to adjust the voltage applied to the fan, which in turn changes the fan’s speed.
3-Wire Fan Wiring Diagram
The wiring diagram of a 3-wire fan is relatively simple. The fan has three wires, namely ground, power, and tachometer. The fan’s wires must be connected to the motherboard or fan controller following a specific wiring diagram. The wiring diagram for a 3-wire fan is as follows:
| Wire Color | Description |
|---|---|
| Black | Ground |
| Red | Power |
| Yellow | Tachometer |
The black wire must be connected to the ground pin of the motherboard, the red wire must be connected to the power pin of the motherboard, and the yellow wire must be connected to the tachometer pin of the motherboard.
FAQs
What is the purpose of a 3-wire fan?
A 3-wire fan is a type of fan with three wires, namely ground, power, and tachometer. The fan receives power through the power wire and uses the ground wire for the return path. The tachometer wire provides the fan’s speed feedback to the motherboard or fan controller. The purpose of a 3-wire fan is to keep the temperature under control by regulating the fan’s speed.
What is the difference between a 2-wire fan and a 3-wire fan?
The main difference between a 2-wire fan and a 3-wire fan is the absence or presence of the tachometer wire. A 2-wire fan has only two wires, namely ground and power, while a 3-wire fan has three wires, namely ground, power, and tachometer. The tachometer wire in a 3-wire fan provides the fan’s speed feedback to the motherboard or fan controller.
What is PWM?
PWM stands for pulse width modulation. It is a method of regulating the voltage and speed of a fan. The controller in a 3-wire fan uses a PWM signal to adjust the voltage applied to the fan, which in turn changes the fan’s speed. The PWM signal is a digital signal that controls the power delivered to the fan.
Can I use a 3-wire fan on a 4-pin header?
Yes, you can use a 3-wire fan on a 4-pin header. The fourth pin on the 4-pin header is for PWM control, which is not present in a 3-wire fan. The 3-wire fan will operate at a fixed speed when connected to a 4-pin header.
What happens if I connect the wires incorrectly?
If you connect the wires incorrectly, the fan will not function properly. The black wire must be connected to the ground pin of the motherboard, the red wire must be connected to the power pin of the motherboard, and the yellow wire must be connected to the tachometer pin of the motherboard. Connecting the wires incorrectly can cause damage to the fan, motherboard, or both.
Conclusion
A 3-wire fan is an essential component in electronic devices to keep the temperature under control. The wiring diagram of a 3-wire fan is relatively simple, with three wires, namely ground, power, and tachometer. The fan’s wires must be connected to the motherboard or fan controller following a specific wiring diagram. The controller in a 3-wire fan utilizes a pulse width modulation (PWM) signal to regulate the fan’s voltage and speed. The PWM signal is a digital signal that controls the power delivered to the fan.
