电路实验室仪器设计——基于恒流源的线性刻度欧姆表  

Instrument Design of Circuit Laboratory——Linear Scale Ohmmeter Based on Constant Current Source

作　　者：崔建国 宁永香 Cui Jianguo;Ning Yongxiang(Shanxi Engineering and Technology College, Yangquan Shanxi 045000, China)

机构地区：[1]山西工程技术学院,山西阳泉045000

出　　处：《山西电子技术》2020年第2期15-16,31,共3页Shanxi Electronic Technology

摘　　要：传统欧姆表表盘刻度呈非线性绘制,若希望欧姆表表盘绘制呈线性状态,需要一个恒流源馈电给受测试的电阻,那么待测电阻的压降将与电阻大小呈正比例线性关系,该恒流源可以由一个同相比例运算电路提供:如果同相比例运算电路输入信号电平固定不变,反馈电阻回路的电流只与补偿电阻有关而与反馈电阻大小无关;如果将待测电阻置于反馈电阻位置、同时测量档位选择电阻置于补偿电阻位置,那么无论在哪一个电阻测量档位,通过待测电阻回路的电流是固定不变的,该恒流源可以保证欧姆表表盘呈线性绘制。The scale of traditional ohmmeter dial is drawn in a non-linear way.If the drawing of ohmmeter dial is expected to be linear,a constant current source is needed to feed the tested resistor,and then the voltage drop of the resistor to be measured will be proportional to the size of the resistor.The constant current source can be provided by an in-phase proportional operation circuit:if the input signal level of the in-phase proportional operation circuit is fixed,the current of the feedback resistance circuit is only related to the compensation resistance and is independent of the feedback resistance size.If the resistance to be measured is placed in the position of the feedback resistance and the gear selection resistance to be measured is placed in the position of the compensating resistance,then no matter where the resistance is measured,the resistance to be measured is passed through the resistance to be measured.The current of the loop is fixed and constant.The constant current source can ensure that the ohmmeter dial is drawn linearly.

关 键 词：同相比例运算器 反馈电阻 补偿电阻 恒流源 线性 

分 类 号：TP271[自动化与计算机技术—检测技术与自动化装置]