Notes from the Physics Teaching Lab: A Magneto-Mechanical Harmonic Oscillator

TL;DR

This paper presents a magnetically driven torsional oscillator designed for physics education, enabling hands-on experiments with tunable damping and optical read-outs that accurately demonstrate simple harmonic motion.

Contribution

It introduces a practical, tunable, and easy-to-measure harmonic oscillator for teaching physics concepts through quantitative experiments.

Findings

The oscillator operates at 40 Hz with high accuracy to simple harmonic motion.

Eddy-current damping effectively tunes the mechanical Q of the system.

Optical read-outs allow straightforward electronic signal recording.

Abstract

We describe a magnetically driven torsional oscillator that is well suited for teaching the physics of simple harmonic motion using a collection of hands-on, quantitative experiments. The mechanical Q of the system can be tuned using eddy-current damping, while optical read-outs provide electronic signals than can be recorded using nothing more than a basic digital oscilloscope. The 40-Hz oscillator is described by simple harmonic motion to high accuracy, providing many satisfying comparisons between theory and experiment.