PWM a 3-pin PC fan with an Arduino - Bald Engineer

Use a PNP transistor to PWM a 3-pin PC Fan with an Arduino. Because of how PNP transistors work, you'll need to use a NPN driver as well.

3 pin PC fan - Project Guidance - Arduino Forum

PWM a 3-pin PC fan with an Arduino - Bald Engineer

Control PWM Fans with an Arduino

3-Wire fan speed control - Project Guidance - Arduino Forum

Converting PWM to 0-12V Analog DC - General Electronics - Arduino Forum

3-Pin Fan Deceleration Line DGZZI Male-to-Female CPU Fan PWM Cable,Temperature Control Descending Speed line for Computer PC Case Fan RPM Connector Resistor Cable Fan Mute line : Electronics

Teensy 4.0 Brings 600 MHz Cortex-M7 to the Arduino World, by James Lewis

Arduino Fan Control // 2-Wire, 3-Wire, and 4-Wire CPU Fan Speed Control and Measurement

PWM a 3-pin PC fan with an Arduino - Bald Engineer

Arduino PWM Fan Controller – Microcontroller Based Projects

Arduino Internal Pull-Up Resistor Tutorial - Bald Engineer

PWM a 3-pin PC fan with an Arduino - Bald Engineer