Pushing a Foucault Pendulum with an Arduino

A Foucault pendulum is a popular exhibit found in many physics buildings and science museums around the world. A typical Foucault pendulum consists of a heavy bob attached to a long cable and has a period of several seconds. Its precession is a function of the latitude and is of order 10 degrees/hour at locations in the continental US. Even the heaviest pendulum is subject to energy loss due to air drag and other dissipative processes and will eventually stop. Therefore some kind of a drive is required to keep the pendulum going without affecting the Foucault precession unduly. Miami's Physics Department is moving into a new building later this year, and we will use this opportunity to upgrade our magnetic drive system and also design a detector for indicating and recording the precession of the pendulum. This presentation shows different forms of drives that can be employed and discussed the advantages of each, as well as some problems that are encountered when working with Foucault pendula.