【摘要】 论述了两种无损耗电阻用于直流电机调速的原理，证明了通过控制开关通断时间，可改变电机电枢电压，从而实现无级直流调速。实验表明，这是一种可行的调速方式。更多还原

【Abstract】 This paper has expounded the principle about two type of loss-less resistors which was used for direct current motor speed governing, and has proved that motor voltage could be changed by controlling time of turning switch on or off to realize continuous direct current motor speed governing. The experiment shows that this method is a practical speed governing method.更多还原