一种高精度数字无源电阻箱的设计与实现

Design and Implementation of a High-Precision Digital Passive Resistance Box

为了降低数字无源电阻箱电磁继电器导通电阻引入的输出电阻误差,文章提出一种高精度数字无源电阻箱的设计和实现方法。与传统的电阻箱相比,具有精度高、可大功率、占用单片机IO口少、操作方便等优点。实验数据表明,档位数N=5,分辨率R=0.1Ω时,输出无源电阻的阻值范围为1.1Ω~11112.1Ω,精度为±0.5%,可广泛应用于模拟电阻式的传感器、自动控制等领域。

In order to reduce the output resistanceerror caused by the on-resistance of electromagnetic relay in digital passive resistance box, a design and implementation method of high-precision digital passive resistance box is proposed. Compared with the traditional resistance box, it has the advantages of high precision, high power, less occupation of MCU IO port, convenient operation and so on. The experimental data show that when the gear number N = 5 and the resolution R = 0.1 Ω, the resistance range of the output passive resistance is 1.1 Ω~11112.1 Ω, and the accuracy is ±0.5%. It can be widely used in the fields of analog resistive sensors, automatic control and so on.