Abstract
Pwm control technology is widely used in control of the areas of technology, the principle is using impulse and not equal to the shape of the same narrow pulse on the part of inertia, the effect of the basic spirit
This article is based on the mos irf540 stc89c52rc monolithic integrated circuits and motors, irf9540 pwm machinery velocity modulation control. the change of pwm for the implementation of the motor than the accelerating, decelerating, inverting, and so on function.Article is based on stc89c52rc monolithic integrated circuits of a direct motor pwm machinery velocity modulation system for research.It finished the total Project design of system and model selection .The hard ware and software design of the system according to the Preceding solutions are discussed detailed. For the hardware Part after a dissertation on the whole design，the core hardware of the control system is the STC89C52RC MCU ，the Paper introduced electrical circuits ，input circuit of keyboard and so on . The method of software Planning for it is also discussed. For the software Part，with the Introduction of modular design concept some Procedure flow charts of main Program subroutine are offered.
Keywords：Direct-current velocity modulation PWM control Mcu
