Modeling the magnetic pickup of an electric guitar

Abstract

The magnetic pickup of an electric guitar uses electromagnetic induction to convert the motion of a ferromagnetic guitar string to an electrical signal. Although the magnetic pickup is often cited as an everyday application of Faraday’s law, few sources mention the distortion that the pickup generates when converting the motion of a string to an electric signal, and fewer analyze and explain this distortion. We model the magnet and ferromagnetic wire as surfaces with magnetic charge and construct an intuitive model that accurately predicts the output of a magnetic guitar pickup. This model can be understood by undergraduate students and provides an excellent learning tool due to its straightforward mathematics and intuitive algorithm. Experiments show that it predicts the change in a magnetic field due to the presence of a ferromagnetic wire with a high degree of accuracy.