While using PWM (Pulse Width Modulation) based fan speed control in PC environments is usually straightforward and does not require any background knowledge, it can be vital when it comes to controlling fans via PWM in other environments. 

Please refer to our specification white paper for a detailed technical documentation of the PWM speed control features of Noctua’s 4-pin PWM fans. Detailing aspects such as connector types, pin configuration or RPM speed signal output as well as signal specifications and circuit design questions, it enables engineers to implement PWM based speed control for Noctua fans in custom circuit designs and applications.