Mount a gimballed compass (one of those magnetic field detectors available
from Cenco, etc) near an open coil. Drive the coil with a function
generator. With a little experimentation you can find a frequency and
amplitude combination which will drive the dip needle into chaotic
oscillations.
--
George Spagna ******************************************
Department of Physics * *
Randolph-Macon College * "Imagination is more important *
P.O. Box 5005 * than knowledge." *
Ashland, VA 23005-5505 * *
* - Albert Einstein *
phone: (804) 752-7344 * *
Internet: gspagna@rmc.edu ******************************************