Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical Applications

This paper addresses the challenges of selecting a suitable method for negative temperature coefficient (NTC) thermistor-based temperature measurement in electronic devices. Although measurement accuracy is of great importance, the temperature calculation time represents an even greater challenge si...

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Main Authors: Marko Petkovšek, Mitja Nemec, Peter Zajec
Format: Article
Language:English
Published: MDPI AG 2021-09-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/9/18/2266
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author Marko Petkovšek
Mitja Nemec
Peter Zajec
author_facet Marko Petkovšek
Mitja Nemec
Peter Zajec
author_sort Marko Petkovšek
collection DOAJ
description This paper addresses the challenges of selecting a suitable method for negative temperature coefficient (NTC) thermistor-based temperature measurement in electronic devices. Although measurement accuracy is of great importance, the temperature calculation time represents an even greater challenge since it is inherently constrained by the control algorithm executed in the microcontroller (MCU). Firstly, a simple signal conditioning circuit with the NTC thermistor is introduced, resulting in a temperature-dependent voltage <i>U<sub>T</sub></i> being connected to the MCU’s analog input. Next, a simulation-based approximation of the actual temperature vs. voltage curve is derived, resulting in four temperature notations: for a look-up table principle, polynomial approximation, <i>B</i> equation and Steinhart–Hart equation. Within the simulation results, the expected temperature error of individual methods is calculated, whereas in the experimental part, performed on a DC/DC converter prototype, required prework and available MCU resources are evaluated. In terms of expected accuracy, the look-up table and the Steinhart–Hart equation offer superior results over the polynomial approximation and <i>B</i> equation, especially in the nominal temperature range of the NTC thermistor. However, in terms of required prework, the look-up table is inferior compared to the Steinhart–Hart equation, despite the latter having far more complex mathematical functions, affecting the overall MCU algorithm execution time significantly.
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spelling doaj.art-92dd657409ed4b80b9e15368e2609bf02023-11-22T14:05:49ZengMDPI AGMathematics2227-73902021-09-01918226610.3390/math9182266Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical ApplicationsMarko Petkovšek0Mitja Nemec1Peter Zajec2Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, SloveniaFaculty of Electrical Engineering, University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, SloveniaFaculty of Electrical Engineering, University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, SloveniaThis paper addresses the challenges of selecting a suitable method for negative temperature coefficient (NTC) thermistor-based temperature measurement in electronic devices. Although measurement accuracy is of great importance, the temperature calculation time represents an even greater challenge since it is inherently constrained by the control algorithm executed in the microcontroller (MCU). Firstly, a simple signal conditioning circuit with the NTC thermistor is introduced, resulting in a temperature-dependent voltage <i>U<sub>T</sub></i> being connected to the MCU’s analog input. Next, a simulation-based approximation of the actual temperature vs. voltage curve is derived, resulting in four temperature notations: for a look-up table principle, polynomial approximation, <i>B</i> equation and Steinhart–Hart equation. Within the simulation results, the expected temperature error of individual methods is calculated, whereas in the experimental part, performed on a DC/DC converter prototype, required prework and available MCU resources are evaluated. In terms of expected accuracy, the look-up table and the Steinhart–Hart equation offer superior results over the polynomial approximation and <i>B</i> equation, especially in the nominal temperature range of the NTC thermistor. However, in terms of required prework, the look-up table is inferior compared to the Steinhart–Hart equation, despite the latter having far more complex mathematical functions, affecting the overall MCU algorithm execution time significantly.https://www.mdpi.com/2227-7390/9/18/2266NTC thermistortemperature measurementmicrocontrollercontrol algorithmcalculation timepower electronics
spellingShingle Marko Petkovšek
Mitja Nemec
Peter Zajec
Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical Applications
Mathematics
NTC thermistor
temperature measurement
microcontroller
control algorithm
calculation time
power electronics
title Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical Applications
title_full Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical Applications
title_fullStr Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical Applications
title_full_unstemmed Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical Applications
title_short Algorithm Execution Time and Accuracy of NTC Thermistor-Based Temperature Measurements in Time-Critical Applications
title_sort algorithm execution time and accuracy of ntc thermistor based temperature measurements in time critical applications
topic NTC thermistor
temperature measurement
microcontroller
control algorithm
calculation time
power electronics
url https://www.mdpi.com/2227-7390/9/18/2266
work_keys_str_mv AT markopetkovsek algorithmexecutiontimeandaccuracyofntcthermistorbasedtemperaturemeasurementsintimecriticalapplications
AT mitjanemec algorithmexecutiontimeandaccuracyofntcthermistorbasedtemperaturemeasurementsintimecriticalapplications
AT peterzajec algorithmexecutiontimeandaccuracyofntcthermistorbasedtemperaturemeasurementsintimecriticalapplications