variable frequence variable speed

• 变频

variable frequence variable speed的用法和样例：

例句

1. The imported frequency control of motor speed adapts to different printing speeds.
   进口变频电机调速，适应不同印刷速度。
2. The doffer is driven by an inverter and a synchronous toothed belt which permits stepless variations of the speed.
   道夫采用变频电机，同步齿形带传动，实现无级调速。