Improvement of the Current Loop Circuit for AC and DC Applications Based on Digital Signal Processing

This paper presents the advanced digital modifications of the conventional DC Anderson current loop circuit for impedance transducers as presented by Anderson (1998). The statistical DSP algorithms of current loop responses are applied for diminishing of measurement errors. The improved DC loop circuit used for absolute resistance measurement with high precision is offered. The experimental result showing the advantages of described circuit are presented. The AC loop circuit has some additional advantages such as possibility to operate with any type of resistance or reactance sensors, and considerable increase in accuracy and quality of measurements to be compared with AC bridges. The results obtained are dedicated to replace high-accuracy and expensive measuring bridges with current loop circuits