This issue is about the DC motor speed control system of PWM pulse width, the design can achieve the direction and speed control of DC motor. This article gave a comprehensive explanation about the basic characteristics of DC motor, DC Motor control principle, DC speed control mode and speed control characteristics, as well as the basic principle and implementation of PWM. Meanwhile, briefly described and analyzed the MCU AT89C51, L298 motor driver module, circuit simulation in proteus simulation software and keil compile software.
Using AT89C51 microcontroller control system as core of the whole circuit and with various shows, drive module to achieve the direction and speed control of DC motor. The circuit consists of the command input module, driver module and display module.And using stand-alone keyboard with interrupting as a command input.AT89C51 exported PWM waveform under the control of program and drive module changed the direction of DC motor. PWM speed control used in this design through changing the pwm duty cycle change the motor armature voltage, so as to realize the speed control of motor. Finally making the circuit simulation with proteus and keil software.
Key words: DC motor,PWM regulating system,AT89C51,PROTEUS,KEIL