目前有刷直流电机转速测量方法或需要电机有外露的旋转部分或要固定到电机壳体内部，成本较高且不适合 作为测量仪表。为此，笔者设计了一款无接触有刷直流电机测速系统，该系统以IAP15W4K58S4 单片机为核心，采集有刷直流 电机换向时产生脉冲电流并向空中辐射电磁波，根据直流电机转速与脉动电流和电磁波频率关联的原理来实现对电动机转速 测量。

The current brush DC motor speed measurement method either needs exposed rotating part of motor or needs to fixed to the motor shell, which has high cost and is not suitable as measuring instruments. Therefore, the author designs a non-contact Brush DC motor speed measurement system. The system mainly uses IAP15W4K58S4 MCU as the core and collects the reversing pulse current of the brush DC motor which radiates electromagnetic wave into the air. According to the correlation of the speed and the pulsating DC motor current with electromagnetic wave frequency, the goal of motor speed measurement can be achieved.