RC time constant measurement using an INA219 sensor: creating an alternative, flexible, low-cost configuration that provides benefits for students and schools

Abstract

In this work, we have developed an alternative device composed by an Arduino board and an INA219 sensor to experimentally obtain the mathematical formulas describing the charge and discharge of the capacitor for educational proposes. We have obtained excellent agreement between theoretical prediction and experimental measurements. The INA219 DC sensor can measure direct current up to 26 V/3.2 A with a maximum error accuracy of 1%. The device makes it possible to follow the temporal evolution of the voltage and the current at a capacitor’s terminals. This platform can provide an alternative way for educational use compared to the expensive laboratory equipment (oscilloscope, voltmeter, generator). Indeed, we think that the presented device can play a dominant role in teaching and learning electricity courses in secondary schools due to its low cost, small size, reliability in measurements and good level of accuracy.