采用单片机AVR mega16作为控制系统的核心，以4*4的小键盘为输入设备，以反射式红外发射-接收器为数据采集部件，用L298N芯片组成功率放大电路驱动电机，四连排数码管作为显示电路的部件，利用直流稳压电源供电，用数码管显示电机的转速，完成对电机的转速、转向、启停等多种工作状态进行快速而准确的控制，组成了一个比较完整电机控制及转速显示闭环系统。-This design uses a singlechip AVR mega16 to be the core device of the control system and use a little keyboard of　4*4 to be the import equipment.At the same time,this design includes a reflecting infrared send-receive implyment to be the data collece equipment and include a L298N chip to consist the power enlarge circuit which is used to drive the electric machinery.The numerical code tube is used to be the implyment of the display circuit. This design use direct current regulated power supply to provide power.All these above consist of a whole electric machinery drive and rotate speed showed closed loop system.On the basic of the basal hardware circuit,the system use a method that control arithmetic of impulse and duty ratio to achieve the direct current electric machinery’s mensuration 、display and control.This design can achieve quick and accurate control of the electric machinery’s rotate speed and turnaround and start-stop and many other work stats.