Using a reed switch to measure the angular speed of a fidget spinner

摘要

We have designed an Arduino-based setup to study the angular speed of a fidget spinner. The apparatus uses a reed switch to detect the magnetic field of a magnet placed in one of the spinner blades. The time interval between consecutive passages is determined from the switch state, and used to compute the angular speed of the spinner as a function of time. We measure the angular speed of the spinner after giving it an initial speed, and found that dry and viscous dissipative forces have to be considered to accurately fit the experimental data.