采样控制理论中有一个重要结论：冲量相等而形状不同的窄脉冲加在具有惯性的环节上时，其效果基本相同。PWM控制技术就是以该结论为理论基础，对半导体开关器件的导通和关断进行控制，使输出端得到一系列幅值相等而宽度不相等的脉冲，用这些脉冲来代替正弦波或其他所需要的波形。

对不了解PWM的开发人员很有帮助。-Sampling control theory have an important conclusion: the same impulse and different shapes of the narrow pulse increases with the inertia of the link, its effect is basically the same. PWM control technique is the theoretical basis for the conclusion of the semiconductor switching device and the on-off control, so that the output has been a series of equal amplitude and pulse width are not equal, use the pulse to replace the sine wave or other by waveform needs. PWM of the developers do not understand very helpful.