Computer 3 Pin Fan Connector Pinout

Note that chassis and cpu fans may use either 3 pin or 4 pin power connectors.

Computer 3 pin fan connector pinout.

A 3 pin fan connector will be smaller in size than the 4 pin pwm fan connector. A three pin connector is basically power 5 12 volt ground and signal. 4 pin connectors are usually used by cpu fans with higher power consumption. Chassis and cpu fans may use either 3 pin or 4 pin power connectors.

With this type fan speed is typically controlled by increasing or decreasing the voltage over the power wire. Chassis and cpu fans may use either 3 pin or 4 pin power connectors. So these adapters arrived and were much needed. 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.

It is a small thick rectangular in line female connector with two polarizing tabs on the outer most edge of one long side. 3 pin connectors are usually used for the smaller chassis fans with lower power consumption. 3 pin connectors are usually used for the smaller chassis fans with lower power consumption while 4 pin connectors are usually used by cpu fans with higher power consumption. Ground 12 v sense control.

A pwm capable fan is usually connected to a 4 pin connector pinout. Three pin molex connector kk family this molex connector is used when connecting a fan to the motherboard or other circuit board. It will also have three square holes on the front and three wires entering the back. 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. Fans and on board fan headers are backwards compatible. The 3 pin senses fan rpm revolutions per minute. 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.

The image below displaying is the difference between a 4 pin pwm fan connector left and a 3 pin fan connector right. Connectors usually used for computer fans are the following. The signal wire measures how fast the fan is moving without any controls for the fan s speed. 2 pack sata to 3 pin 4 pin pmw 12v pc case fan power adapter cable 3 pin or 4 pin pwm connector to 15 pin sata computer cooler cooling fan power cable 4 0 out of 5 stars 24 7 59 7.

When no revolutions are sensed by the system an audio alarm or no system boot will occur warning the user or preventing proccessor overheating and burnout. 4 pin connectors are usually used by cpu fans with higher power consumption.