Conversion system for PWM signal of cooling fan, involves converting PWM signal to analog voltage signal at different level

摘要

A conversion system for pulse width modulation (PWM) signal of a cooling fan, has an input for the PWM signal through which the PWM signal is inputted. A conversion unit which is joined to the input for PWM signal and the PWM signal is converted into an analog voltage signal with a different level, corresponding to its drive/operating play, and a drive circuit (40) controls the motor speed with the analog voltage signal.