Title :
Design and Analysis of a Dual-Slope Inductance-to-Digital Converter for Differential Reluctance Sensors
Author :
Philip, N. ; George, Boby
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol. Madras, Chennai, India
Abstract :
A new, simple, and high accuracy dual slope inductance-to-digital converter (DSIDC) suitable for differential reluctance sensors is presented in this paper. Differential reluctance sensors have two inductors that vary in a push-pull manner with respect to measurand. In many such sensors, the relationship between inductance and measurand is nonlinear. It is known that a small linear range can be obtained by taking the difference between the values of the sensor inductances. The proposed DSIDC accepts the sensor inductances having nonlinear characteristics and provides a linear digital output directly proportional to the measurand [without employing a dedicated analog-to-digital converter (ADC)]. The output of the DSIDC is linear for the full range of the sensor. As the output is in digital form, it can be easily stored and processed in a digital system. The DSIDC is based on dual-slope ADC principle and possesses many advantages. The effect of various parameters on the performance of the DSIDC was analyzed, quantified, and presented in this paper. A prototype DSIDC has been built and tested with a differential variable reluctance based displacement transducer. Output from the DSIDC was linear for the full range of input.
Keywords :
analogue-digital conversion; displacement measurement; inductance measurement; inductors; sensors; transducers; DSIDC; analog-to-digital converter; differential reluctance sensor; differential variable reluctance; displacement transducer; dual-slope ADC principle; dual-slope inductance-to-digital converter; inductor; linear digital output; nonlinear characteristics; sensor inductance; Delays; Inductance; Inductors; Prototypes; Resistance; Sensors; Switches; Differential reluctance sensor; digital converter; dual slope converter; inductive sensors; signal conditioning;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2013.2296411