一种高精度无源电阻发生器

High-Precision Passive Resistance Generator

针对一般无源电阻发生器存在精度低、稳定性差等问题,提出了一种基于分支定界的高精度无源电阻发生器。模拟各影响因素耦合作用下的实际输出电阻值,确定实际输出值与电阻组合的定量关系,建立电阻输出模拟方程。将模拟方程的求解转化为0-1整数规划问题,并采用分支定界法获得输出值最接近设定电阻值的最优电阻组合,从而有效地减小硬件因素对电阻输出精度的影响。试验结果表明:1.0Ω~1 kΩ分辨力为0.1Ω,1~20 kΩ分辨力为1Ω,系统输出响应时间优于500 ms。本电阻发生器能够满足仪表调校场合对无源电阻器的输出精度要求。

To overcome the low precision and weak robustness of common general resistance generators,a high precision passive resistance generator based on branch and bound algorithm was presented. The quantitative relationship between the output resistance value and resistor combination was got,meanwhile the resistance output simulation equation was established by simulating actual output resistance value influenced by various factors. To compensate the output error of the generator,considering the solution of simulation equation as a 0-1 integer programming problem,the branch and bound algorithm was adopted to obtain the optimal resistor combination whose output resistance value was closest to the preset resistance value. Experimental results show that a resolution of 0. 1 Ω is reached in the range of 1. 0 Ω ~ 1 kΩ and another resolution of 1 Ω is reached in the range of 1 ~ 20 kΩ. The system output response time is less than 500 ms. The resistance generator can meet the output precision requirements of passive resistance generator in instrument calibration.