Motor control system and method

摘要

A motor control system is disclosed. The motor control system includes a level-shifting unit, a motor unit and a control unit. The level-shifting unit receives an original pulse width modulation (PWM) signal to generate an output PWM signal. When a first high level of the original PWM signal is larger than a first reference value, the level-shifting unit shifts a second high level of the output PWM signal to a set high level. When a first low level of the original PWM signal is lower than a second reference value, the level-shifting unit shifts a second low level of the output PWM signal to a set low level. The control unit controls the speed of the motor according to the output PWM signal.

主权项

1. A motor control system, comprising:
a level-shifting unit for receiving an original pulse width modulation (PWM) signal to generate an output PWM signal, wherein the level-shifting unit shifts a second high level of the output PWM signal to a set high level when a first high level of the original PWM signal is larger than a first reference value, and shifts a second low level of the output PWM signal to a set low level when a first low level of the original PWM signal is lower than a second reference value, and the level-shifting unit comprises:
a Zener diode, comprising an anode and a cathode, wherein the cathode receives the original PWM signal; anda switch transistor, comprising:
a voltage control terminal electrically connected to the anode:a first terminal electrically connected to a first voltage source having the set high level and an output terminal, wherein the output terminal generates the output PWM signal; anda second terminal electrically connected to a second voltage source having the set low level; a motor unit; and a control unit for controlling a speed of the motor unit according to the output PWM signal.