Using Raspberry Pi to Control a PWM Fan and Monitor its Speed - DriftKingTW's Blog
Noctua PWM specifications white paper
4. DC Fans Speed Control | Engineering Information | MinebeaMitsumi Product DataBase
120x120x25)mm Brushless Cooling Fan 4-Wire PWM Control – HandsOn Tech
circuit design - 4-wire fan controlled by potentiometer and 555 IC not behaving properly - Electrical Engineering Stack Exchange
Dc 5v 12v 4 Wire Pwm Fan Temperature Control Speed Controller Governor Regulator For Pc Computer Cpu Fan Cooler Alarm Module - Motor Controller - AliExpress
Computer fan control - Wikipedia
Pwm Fan Temperature Controller Adjustable Speed 12v 4-wire - AliExpress