Circuit structure for detecting rotation distance of motor and motor capable of automatically adjusting speed

The invention provides a circuit structure for detecting the rotation distance of a motor and a motor capable of automatically adjusting the speed. The circuit structure comprises a microcontroller, a step-down chopper circuit, a sampling resistor and a ripple signal processing circuit. Wherein the step-down chopper circuit is respectively connected with the microcontroller and the motor and is used for converting a PWM signal into a direct current signal and providing voltage for the motor; the sampling resistor is connected with the motor and is used for acquiring a motor current signal and converting the motor current signal into a voltage signal; the ripple signal processing circuit is respectively connected with the sampling resistor and the microcontroller, and is used for processing the voltage signal and converting the processed voltage signal into a pulse signal; the microcontroller is further used for obtaining the rotation distance of the motor according to the number of the ...