Ventilation cabinet door automatic control system

The invention discloses a ventilation cabinet door automatic control system which comprises a motor and is characterized in that the control end of the motor is electrically connected with a CPUmodulefor controlling the forward and reverse rotation and the rotation speed of the motor, and the input end of the CPU module is electrically connected with an encoder for automatically detecting the rotation direction, the rotation speed, the rotation angle and the number of turns of the motor; the encoder is electrically connected with the input end of the CPU module through an encoder control circuit, the encoder is used for detecting the rotation angle and the number of turns of the motor and the CPU module is enabled to calculate the specific position of the ventilation cabinet door according to the rotation angle and the number of turns, detected by the encoder, of the motor, and the encoder is used for detecting the rotation direction of the motor to enable the CPU module to judge existence of obstacles in the