Dual Slope Direct Digital Converter for Bridge Connected Resistive Sensors


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International Journal on Smart Sensing and Intelligent Systems

Professor Subhas Chandra Mukhopadhyay

Exeley Inc. (New York)

Subject: Computational Science & Engineering , Engineering, Electrical & Electronic


eISSN: 1178-5608



VOLUME 7 , ISSUE 5 (December 2014) > List of articles

Special issue ICST 2014

Dual Slope Direct Digital Converter for Bridge Connected Resistive Sensors

Ponnalagu R. N / Boby George / Jagadeesh Kumar V

Keywords : Direct digital converter; Resistive sensors; Strain gauges; Wheatstone bridge; Instrumentation amplifier; Dual slope digital converter

Citation Information : International Journal on Smart Sensing and Intelligent Systems. Volume 7, Issue 5, Pages 1-5, DOI: https://doi.org/10.21307/ijssis-2019-070

License : (CC BY-NC-ND 4.0)

Published Online: 15-February-2020



A dual slope direct digital converter (DSDDC) suitable for resistive sensor elements already connected in a bridge form is presented. A conventional dual slope analog to digital converter (DS-ADC) is altered with an intentionally introduced instrumentation amplifier (INA) to realize the proposed DDC. The DSDDC accepts bridge connected resistive sensor elements as input and provides a digital output that is proportional to the quantity being sensed by the sensor elements. The results obtained from simulation of the proposed DSDDC indicate a worst case error in the output to be < ±0.03 %. Experimental results from a prototype unit, presented herein, demonstrate the practicality the scheme. Worst case error of the prototype unit was found to be < ±0.07 % with test conducted using standard decade resistance boxes emulating the sensor elements. The worst case error in the prototype was < ±0.05 % when tested with a load-cell made of four strain gauges.

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