模块化数字可编程微小电阻的设计与应用

Design and Application of Modular Digital Programmable Micro Resistor

针对微小电阻测试仪中电阻量值的检定需求,设计了一种基于线性网络的小阻值可变电阻。设计的高准确度线性网络具有较小电阻调节步进;采用高准确度线性网络解决了小电阻步进的问题;选用逐次逼近自适应算法解决了可变电阻静态温漂的问题。为了避免表面气流温度突变带来不稳定,设计了分区域防风罩作为温度缓冲器。检定结果表明,可变电阻达到最大允许误差为±0.3%。满足最大允许误差为±1%的微小电阻测试仪的量值传递及小型化适用性需求。

According to the verification of resistance measurement in the micro resistance measuring instru- ment, a small resistance variable resistor based on linear network is designed. The high accuracy linear network has a small step to adjust the resistance. The successive approximation adaptive algorithm is used to solve the problem of static temperature drift of variable resistor. In order to avoid the instability caused by the sudden temperature change of the airflow, the regional wind proof cover is designed. The results show that the resolu- tion of the variable resistance is up to 0. 3 %. It can meet the requirement of micro resistance measuring instru- ment with a resolution of 1%, and has the advantages of miniaturization.