基于单片机的转速测量及输出4～20mA电流的系统设计

摘要

This paper mainly discussed the generation of standard current（4～20 mA） from wheel speed with the help of a control system designed.This system runs under direct current power supply and through voltage-reduce treatment provides operating voltage of 5 V for MCU.MCU will then collect and process the signals of wheel speed before MAX538 transforms the processed digital value into voltage.AD694 finally converted the transformed voltage into standard current（4～20 mA） to support the subordinate devices.%针对工业标准电流4～20 mA的产生,设计了一套将车轮转速转换成标准电流输出的控制系统。该系统采用24 V直流电源供电,经降压处理给单片机提供＋5 V的工作电压,然后由单片机实现对车轮转速信号的采集、处理,数/模转换器MAX538则把处理后的数字量转换成电压,并借助电压/电流转换器AD694将电压转换成4～20 mA的电流供给后级设备。