Module for experiment to demonstrate principle of automatic control

The utility model provides a module for an experiment to demonstrate the principle of automatic control. The module comprises a motor driving unit, a power output terminal and a PWM (pulse width modulation) signal output terminal, wherein the motor driving unit is provided with a DC (direct current) motor and a motor driving circuit; the power output terminal is used for receiving the parameters for scale, integral and differential control from an experiment platform and providing the controlled voltage for the motor driving circuit according to the received parameters; the PWM signal output terminal is used for receiving PWM signals from the experiment platform and providing PWM control signals for the motor driving circuit according to the duty ratio of the received PWM signals; the motor driving unit is used for outputting the pulse signals representing the rotating speed of the DC motor according to the controlled voltage and the PWM control signals; and the motor driving circuit comprises a pulse signal