一种二线制电流型电阻变送器的电路设计  

Circuit design for two-wire current-resistance transmitter

作　　者：余波[1] 梁雪松[1] 

机构地区：[1]成都师范学院物理与电子技术系,成都611130

出　　处：《电子测量技术》2014年第1期20-23,共4页Electronic Measurement Technology

摘　　要：设计了一种二线制电流型电阻变送器,能把1 000～2 000 Ω的电阻量转化为4～20 mA的电流量.该变送器由1片运算放大器芯片构成信号调理电路与二线制V/I转换电路,运用零温度系数的恒流源作为被测电阻的激励信号,具有电路简单、线性度高、性能稳定和成本低等特点,且不存在智能仪器可能出现的程序跑飞、死机等异常情况.测试结果表明,精度为0.1级,工作电源电压范围为15～30 V.This paper designs a two wire current-resistance transmitter,which can transform 1 000--2 000 ~ resistance into 4--20 mA current. The transmitter applies an operational amplifier chip to make up a signal conditioning circuit and a two wire V/I conversion circuit,and uses constant current source with zero temperature coefficient as excitation signal measured resistance. It has some characteristics of simple circuit ,high linearity, stable performance and low cost etc, and has no potential abnormalities such as programm fleet,system halted in the intelligent instruments . Test results show that it attains the accuracy of 0.1 grade,and has the working power supply voltage range of 15V to 30 V.

关 键 词：变送器 二线制 运算放大器 LM334 

分 类 号：TM93[电气工程—电力电子与电力传动]