Direct inductive sensor-to-microcontroller interface circuit

This paper proposes and analyses a microcontroller-based interface circuit for inductive sensors with a variable self-inductance. Besides the microcontroller (mu C) and the sensor, the circuit just requires an external resistor and a reference inductor so that two RL circuits are formed. The mu C ap...

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Bibliographic Details
Authors: Kokolanski, Zivko, Jordana Barnils, José|||0000-0002-8498-8700, Gasulla Forner, Manuel|||0000-0002-0364-6806, Dimcev, Vladimir, Reverter Cubarsí, Ferran|||0000-0003-1653-0519
Format: article
Publication Date:2015
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/86844
Online Access:https://hdl.handle.net/2117/86844
https://dx.doi.org/10.1016/j.sna.2015.01.017
Access Level:Open access
Keyword:Detectors
inductive sensor
microcontroller
sensor electronic interface
Àrees temàtiques de la UPC::Enginyeria electrònica
Description
Summary:This paper proposes and analyses a microcontroller-based interface circuit for inductive sensors with a variable self-inductance. Besides the microcontroller (mu C) and the sensor, the circuit just requires an external resistor and a reference inductor so that two RL circuits are formed. The mu C appropriately excites such RL circuits in order to measure the discharging time of the voltage across each inductor (i.e. sensing and reference) and then it uses such discharging times to estimate the sensor inductance. Experimental tests using different commercial mu Cs at different clock frequencies show the limitations (especially, due to parasitic resistances and quantisation) and the performance of the proposed circuit when measuring inductances in the millihenry range. A non-linearity error lower than 0.3% full-scale span (FSS) and a resolution of 10 bits are achieved, which are remarkable values considering the simplicity of the circuit. (C) 2015 Elsevier B.V. All rights reserved.