一种基于频率/电流转换的4~20mA电路设计  

A based on frequency/current conversion of 4-20 mA circuit design

作　　者：黄伟[1] 庄志红 

机构地区：[1]常州工学院电子信息与电气工程学院,江苏常州213002

出　　处：《电子设计工程》2015年第22期86-88,共3页Electronic Design Engineering

基　　金：2014年国家级大学生创新项目(201411055003)

摘　　要：探讨了3种实现4~20mA电路的方案,比较了其优缺点;重点介绍了利用LM331实现频率/电压转换;再利用运放和三极管构成恒流电路,将电压转换成电流;实现4~20mA输出的频率/电流转换的工作原理,并且给出了具体器件参数和控制程序,验证了相关数据。本电路简单、实用,成本低廉,可广泛应用于单片机、PLC等控制系统中。This article introduced the three methods about 4-20 mA circuit, compared their advantages and disadvantages. In mainly introduced the method about how to use LM331 to complete the frequency/voltage,and use op-amp and transistor to constitute the constant current circuit, to complete voltage/current.The working principle of frequency/current about how to implementation 4-20 mA output. And give out the device parameters and control program in detail.And verify the relevant data.The features of the circuit is simple, practical,and the cost is low,This method can be widely used in single chip microcomputer and PLC control system.

关 键 词：4~20mA LM331 频率/电流 信号转换 

分 类 号：TN792[电子电信—电路与系统]