Title :
A Linear Variable Differential Capacitive Transducer for Sensing Planar Angles
Author :
George, Boby ; Mohan, N. Madhu ; Kumar, V. Jagadeesh
Author_Institution :
Tech. Univ. of Graz, Graz
fDate :
4/1/2008 12:00:00 AM
Abstract :
A linear variable differential capacitive transducer for the measurement of planar angles (from 0deg to 360deg) is presented in this paper. The sensor part of the transducer is made of parallel plates of standard and easy-to-fabricate shapes, and the signal-conditioning electronics are realized, employing a couple of simple relaxation oscillators. The output of the transducer is only dictated by a pair of dc reference voltages, and hence, high accuracy and linearity over the entire range (from 0deg to 360deg) are easily obtained by the use of precision dc reference voltages. Detailed analysis indicates that the sensitivity of the transducer is minimal for variations in different parameters. Experimental results obtained on a prototype transducer that has been built and tested establish the efficacy of the proposed transducer. The worst-case error of the prototype transducer is found to be less than 0.1%.
Keywords :
angular measurement; capacitive sensors; linear variable differential capacitive transducer; parallel plates; planar angles measurement; relaxation oscillators; signal-conditioning electronics; Angle transducer; angular-position measurement; differential capacitive sensor; ratiometric measurement principle; relaxation oscillator;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2007.913597