An interface circuit for measuring small as well as large resistance changes

In this paper we present a new and very simple opamp based transducer bridge amplifier circuit which is used to measure resistance changes. It is cable of measuring small as well as large resistance changes. It is a low cost structure, owing to its use of only one resistive element. Furthermore, it uses single calibrating resistor which can take care of many non-ideal effects on the part of opamp and that due to tolerances of resistor and power supply. Simulation performed using SPICE of the proposed circuit and the experimental result obtained in the lab confirms the idea presented in this work.