一种基于运算放大器的高灵敏度惠斯通电桥  

A Highly Sensitive Wheatstone Bridge Based on Operational Amplifier

作　　者：何华平 徐伟 何立蜓 黄俊华 陈平[2] He Huaping;Xu Wei;He Liting;Huang Junhua;Chen Ping(College of Computer and Information Science,Southwest University,Chongqing400715;School of Physical Science and Technology,Southwest University,Chongqing400715;Chongqing Songshuqiao Middle School,Chongqing401147)

机构地区：[1]西南大学计算机与信息科学学院,重庆400715 [2]西南大学物理科学与技术学院,重庆400715 [3]重庆市松树桥中学校,重庆401147

出　　处：《物理通报》2022年第3期121-126,共6页Physics Bulletin

基　　金：西南大学2021年实验技术研究项目,项目编号:SYJ2021032;国家级“大学生创新创业训练计划”项目,项目编号:202110635095。

摘　　要：关于如何提升惠斯通电桥灵敏度一直是惠斯通电桥研究的热门话题.运算放大器组装成为的差分放大电路在一定范围内可以线性放大输入电压.但是,使用运算放大器提高电桥灵敏度的方法并未被采用.本文采用LM358N型运算放大器来提高电桥两端电势差的测量精度,从而提升惠斯通电桥的灵敏度.我们使用Multisim软件对该方案进行仿真,结果表明如果将放大倍数调至20倍,那么实际误差将小于2%.经过对改进电桥进行实际测量,实验和理论结论符合得很好.采用此方法可以得到一个易操作、低成本、高灵敏度的惠斯通电桥.Improving the sensitivity of Wheatstone Bridge has always been a hot topic in Wheatstone Bridge research.The differential amplifier can linearly amplify the input voltage within a certain range.However,the application of operational amplifiers to improve the bridge sensitivity has not been reported.In this paper,LM358N operational amplifier is used to improve the sensitivity of Wheatstone bridge by increasing the measurement accuracy of the potential difference between the two ends of the bridge.The Multisim software is used to simulate the assumption,and the results show that the actual error will be less than 2%if the magnification is adjusted to 20 times.Through the actual measurement of the improved bridge,the experimental results are in good agreement with the theoretical calculating.By using this method,a Wheatstone bridge with easy operation,low cost and high sensitivity can be obtained.

关 键 词：惠斯通电桥 差分放大电路 灵敏度 

分 类 号：O441.1[理学—电磁学]