Computer 3 Pin Fan Connector Pinout

4 pin connectors are usually used by cpu fans with higher power consumption.

Computer 3 pin fan connector pinout.

The 3 pin senses fan rpm revolutions per minute. 4 pin connectors are usually used by cpu fans with higher power consumption. Fans and on board fan headers are backwards compatible. With this type fan speed is typically controlled by increasing or decreasing the voltage over the power wire.

The signal wire measures how fast the fan is moving without any controls for the fan s speed. Typically the motherboard is required to pull the pin up through a resistor with the fan connecting it to ground once or more per revolution. Fans with three pin connectors must be used on 3 pin cpu fan pinouts. 3 pin connectors are usually used for the smaller chassis fans with lower power consumption.

On space constricted fan control hubs the 4 pin connector failed to lock onto the fan s wire leading to the adapter falling off the fan s wire lead. Ground 12 v sense control. Note that chassis and cpu fans may use either 3 pin or 4 pin power connectors. It will also have three square holes on the front and three wires entering the back.

The image below displaying is the difference between a 4 pin pwm fan connector left and a 3 pin fan connector right. 3 pin connectors are usually used for the smaller chassis fans with lower power consumption. The sense pin is used to relay the rotation speed of the fan and the control pin is an open drain or open collector output which requires a pull up to 5 v or 3 3 v in the fan. So these adapters arrived and were much needed.

Three pin molex connector kk family this molex connector is used when connecting a fan to the motherboard or other circuit board. A pwm capable fan is usually connected to a 4 pin connector pinout. Connectors usually used for computer fans are the following. While they look nice and do adapt 4 pin fans to 3 pin outlets esp.

A 3 pin fan connector will be smaller in size than the 4 pin pwm fan connector. Chassis and cpu fans may use either 3 pin or 4 pin power connectors. It is a small thick rectangular in line female connector with two polarizing tabs on the outer most edge of one long side. A three pin connector is basically power 5 12 volt ground and signal.

But after attempting to use them they worked out pitifully. Chassis and cpu fans may use either 3 pin or 4 pin power connectors.