Research on the smart measuring system for DC resistance box
Wenbo Xie, Sheng Hao Wu, Shan Li, Yang Li, Helei Wu · Journal of Physics Conference Series · 2018
Aiming at the shortages existing in the process of measuring DC resistance box's resistance, this paper proposes a new smart electric bridge. The relationship between the voltage of electric bridge and the value of programmable constant voltage module is discussed using Wheatstone bridge theory. The voltage of electric bridge is obtained by ADC device and the value of programmable constant voltage module is controlled by DAC device. According to the mathematical equation between physical quantities of electric bridge, when the bridge balanced, the system calculates the value of DC resistance box's resistance. In this study, ratio knob switching circuit is designed to change the value of DC resistance box's resistance automatically. Experimental results show that the measuring accuracy of the system is 1/10000, Stability reached 5/100000 and the system is easy operating, high working efficiency.