DC motor PWM speed regulation system and method

The invention belongs to the technical field of electronics, and discloses a DC motor PWM speed regulation system and method aiming at the problem that a traditional speed regulation mode cannot meet the requirements of some occasions needing precise rotating speed and quick response. The DC motor PWM speed regulation system comprises a single chip microcomputer U1, a driving chip U2, a direct current motor, a power supply module, a key adjusting module, an enabling chip U3, a display D1, a display D2, a crystal oscillator X1, a serial port communication module and other peripheral circuits. According to the DC motor PWM speed regulation system, the single chip microcomputer AT89C52 is used as a core, the direct current motor is subjected to steering and speed control through using the driving chip L293D special for the direct current motor, and meanwhile a current rotating speed and an expected rotating speed of the direct current motor are displayed through using an LED nixie tube. According to the system,