Control motor speed design

Single chip microcomputer STM32L151CCU6

RF cable can be customized for other specifications

Mobile phone crystal 3.2*2.5mm 3225 26M (26.000MHZ) 7.5PF 10PPM 20PPM 30PPM

As shown in the figure, the motor speed control circuit. This is a closed-loop control circuit that controls the speed of the fractional horsepower DC motor. It consists of a CD4046 phase-locked loop chip, a phototransistor and peripheral components. A grooved disk is mounted on the motor shaft, and the received pulse frequency fm is detected, and fm is compared with the reference frequency fref outputted by the voltage controlled oscillator in phase. When fm