How To Power 3 Pin Fans

Introduction

Did yous know that you can change any fan located inside your PC – CPU fan, VGA fan, north span fan, instance fan, etc. – to run at three dissimilar speed levels (low, medium and loftier) without spending whatsoever coin at all? This is possible by just changing the configuration of the wires used by the fan. In this tutorial, nosotros will give you detailed instructions on how to do that, thus reducing the noise produced past your PC.

Fans can have 2, three or four wires. Below you accept a breakdown of the function of each pin and the most common colour for the wire attached to that pin. There are two important things to notice here. Commencement, the colour of the wires may change depending on the fan manufacturer. These are the most common ones. Second, all fans are fed with +12 V; withal, several fans utilise a red wire on their +12 V line, which is different from the color code used by the power supply, where ruddy ways +5 5.

Pin	Role	Wire Colour
i	Ground	Black
2	+12 V	Red or Yellow
three	Fan Speed Sensor	Xanthous, White or Green
four	PWM Control	Blue

Also notice that during this tutorial, our examples will use a CPU fan, but everything we say is valid for whatever kind of fan located inside the PC: video card fan, chipset fan, case fan, etc.

In Figures one and 2 you can see a three- and a four-pivot connector, respectively. Discover that the counting is done with the primal present on the connector facing up.

Figure 1: Connector from a CPU fan using 3 pins

Effigy ii: Connector from a CPU fan using 4 pins

Figure 3: CPU fan connector on a motherboard, you lot tin can install either three- or four-pin fan connectors here

The kickoff two pins supply the voltage required for the fan to spin. The third pin is continued to the fan speed sensor, reporting the current fan speed to the motherboard. This value can be read at the motherboard setup (come across Figure 4) or through a monitoring plan, such equally Motherboard Monitor. Finally, the fourth pin is a speed control input, also known every bit a PWM (Pulse Width Modulation) control, provided by the motherboard. On fans that take this fourth pivot, the motherboard (or video carte) can control the speed of the fan, usually automatically depending on the CPU or GPU (graphics chip) load.

Figure 4: Motherboard setup

If your fan has four wires, you don't need to do what nosotros will teach in this tutorial, equally your fan already has a speed command circuit. Simply go to the motherboard setup and await for an option to enable this characteristic ("CPU Smart FAN Command" and setting style to "Auto" in Figure 4). This will reduce the CPU fan speed automatically when your computer is idle or when you lot are not using a "heavy" application such equally a game.

If, all the same, you are not satisfied with the PWM command provided past your computer, you can remove the fourth pin (encounter how in Figures 6 and seven) and execute the procedures described in this tutorial.

Reducing the fan speed is a matter of feeding it with a lower voltage. But how tin can nosotros do that if the fan connector only provides +12 V? That is exactly the play a joke on we will teach yous. We volition remove the fan power wires from the fan connector and install them direct to one of the peripheral power plugs from the power supply. This way, we will exist able to feed the fan with +5 V (low speed), +seven Five (medium speed) and + 12 5 (full speed). Please read on.

Source: https://hardwaresecrets.com/how-to-create-a-three-speed-fan-control-without-spending-a-dime/