Why do CPU fans have 4 wires?

Why do CPU fans have 4 wires?

A 2-wire fan has power and ground terminals. A 3-wire fan has power, ground, and a tachometric (“tach”) output, which provides a signal with frequency proportional to speed. A 4-wire fan has power, ground, a tach output, and a PWM-drive input.

Can you control fan speed with 4 pin?

Thus, you CAN alter the speed of a 4-pin fan by changing the voltage supplied to its Pin #2. (Pin #1 is Ground.) The best way to do this is with a pre-engineered third-party fan speed controller because all the fancy design requirements have been done for you.

Are 4 pin fans always PWM?

PWM fans are always 4 pin fan connectors. The additional wire has the ability to adjust the rotation speed depending on the temperature of the CPU.

Does a CPU fan need 4 pins?

You use 4pin for cpu coolers. They incorporate a pwm pin (high efficiency speed control). You use 3 pin fans for case fans.

How does a 4 pin fan work?

How Does a 4-Pin PWM Fan Work? PWM can be used as a form of voltage control, and that’s exactly what it does for a PWM fan. The fan rotates according to the voltage supplied through the PWM control pin. It is also a way of providing better and smarter control for thermal management of the motherboard.

Where do I connect 4 pin PWM?

If you want to use the PWM function then the 4 Pin fan must be connected to a 4 Pin header on the motherboard. If you connect the 4 Pin fan connector to a 3 Pin header, then the fan will run at maximum RPM. 1.

What is 4pin PWM?

So, why does a 4-pin PWM header exist on a motherboard? The reason is quite simple: The 4-pin PWM header is used to control the cooling fan that’s attached to the enclosure. Most modern motherboards are likely to be equipped with such a header, which is connected to a PWM-supported BLDC fan.

Can an Arduino power a PC fan?

To complete nickn4’s post, the arduino can indeed control the fan speed with PWM. Connect the PWM pin to a transistor, and you can fully control the speed of the fan. PWM is essentially an analogue output, where it can output a specific voltage between 0V and 5V (like 1.5V), instead of just 0V or 5V (On or Off).

How do you wire a 4 wire computer fan?

However, the 4-wire fan is a little different as it has the fourth ‘control’ wire to input a signal to the fan that commands it to speed up or speed down….4-wire fans explained.

Can I connect a 4 pin fan to a 3 pin connector?

Yes! PWM fans come with a 4-pin connectors for fully automatic speed control via your mainboard’s 4-pin PWM fan headers. Please note that 4-pin fans can also be connected to your mainboard’s 3-pin fan headers though.