Date : 24th March, 2017 Time: 3:00 pm
Venue : ESB-244, Electrical Engineering
Speaker: Ponnalagu R. N. (EE12D019)
Guides: Dr. Boby George and Prof. Jagadeesh Kumar V.
DC Members :
Dr.Mahesh Kumar (M)
Dr. Shankarram.C.S (ED)(M)
Dr. Sivanandan.R (CE)(M)
Even though the bridge-based signal conditioning of resistive sensors is in use for several decades, there exists no simple and effective linearization scheme that can provide a digital output, directly, from a bridge configuration that has a non-linear output characteristic. A linearizing direct digital converter suitable for resistive sensors, when connected in a quarter-bridge or half-bridge configuration will be presented in this seminar. The proposed scheme not only digitizes the measurand, but also linearize the output of the Wheatstone bridge which otherwise possesses a significant inherent nonlinearity. The output of the digitizer is independent of the bridge lead resistance, thus, it is well suited for resistive sensors that are remotely located from the converter. The talk will also cover an improved hardware optimized direct sensor to microcontroller interface for single element resistive sensors. The improved scheme compensates the effect due not only to resistances of lead wires but also the effect of microcontroller port pin’s internal resistance and any mismatch that is present between those pins. Since the resistances of lead wires are compensated, automatic temperature compensation (temperature effect of lead wires) is also obtained. Suitable prototypes of the above mentioned schemes have been built and tested in the laboratory. All the possible sources of errors have been identified and the resulting error due to each source has been quantified. The details will be presented in the seminar.
All are cordially invited.