Design of DC Motor PWM Speed ​​Control System Based on 51 Single Chip Microcomputer

Design ideas

The main functions of the DC motor PWM control system include: realizing the acceleration, deceleration, forward rotation, reverse rotation and emergency stop of the DC motor, and adjusting the speed of the motor, which can easily realize the intelligent control of the motor.

Main circuit: DC motor PWM control module. This part of the circuit mainly controls the acceleration, deceleration, forward and reverse rotation of the DC motor by the I/O port, timer counter, external interrupt extension of the AT89C52 microcontroller, and can adjust the motor speed, which can easily realize the intelligent control of the motor. In the meantime, the AT89C52 microcontroller generates a pulse signal with adjustable pulse width and inputs it to the L298 driver chip to control the operation of the DC motor. The DC motor PWM control system consists of the following circuit modules: Design input part: This module mainly uses an independent keyboard with interrupt to realize the acceleration, deceleration, forward rotation, reverse rotation and emergency stop control of the DC motor. Design control part: It is mainly composed of the external interrupt extension circuit of the AT89C52 microcontroller. The DC motor PWM control implementation part is mainly composed of some diodes, motors and L298 DC motor driver modules. Design display part: LED digital display part, to realize the real-time display of PWM pulse width modulation duty cycle.

system framework

The principle is: the DC motor PWM speed control system uses the AT89C52 single-chip microcomputer as the control core, and is composed of a command input module, an LED display module, and a motor drive module. An independent keyboard with interrupts is used as the command input. Under program control, the single-chip microcomputer regularly sends PWM waveforms to the L298 DC motor drive chip, and the H-type drive circuit completes the forward, reverse, and emergency stop control of the motor; at the same time, the single-chip microcomputer continuously sends the PWM pulse width modulation duty cycle to the LED digital tube to complete real-time display.

Simulation circuit diagram

The system results are as follows

This design is detailed, covering the design principle of the single-chip minimum system; the design of buttons and digital tube displays; the principle, method and implementation process of PWM speed regulation; the design principle of L289 motor driver chip; complete Keil c program, etc. It allows you to have a clear understanding of the design process of DC motor PWM speed regulation control system.