脉冲宽度调制[1]（Pulse Width Modulation，缩写为PWM），简称脉宽调制，是利用微处理器的数字输出来对模拟电路进行控制的一种非常有效的技术，广泛应用在从测量、通信到功率控制与变换的许多领域中。脉冲宽度调制的一个优点是从处理器到被控系统信号都是数字形式的，无需进行数模转换-Pulse width modulation ( PWM ), short for PWM, is a very effective technology of the digital output of microprocessor, widely used in many fields　measurement, communication to power control and transformation. The advantage of pulse width modulation is that the signal　the processor to the controlled system is digital form, no need to make a mathematical model conversion.