# Magnetic pendulum

From: Mrcap5@aol.com
Date: Wed Sep 17 2003 - 13:29:37 PDT

I noticed that this snack was removed from your list of snacks. Was that
because it does not work very well?

I was reading a feedback from a father who was trying this project with his
child. He complained that the effect was not great enough and attributed it
to the type of wire he used. He had the very slightest effect using telephone
wire and not magnet wire. So how can the effect be increased? The
magnetic induction causing the force apparently is not very strong. To move an
object most readily, the mass to be moved must be very small. That would include
the coiled wire and the rod supporting the wire. For maximum effect you
want more turns of wire. However, that increases the mass. So the lighter
wire (smaller gauge) makes sense but so would a lighter support rod. The
induced EMF in the wire also depends on the strength of the magnetic field. So,
use a stronger magnet. A cow magnet is strong but not as strong as a
neodymium magnet. They don't make cylindrical neodymium magnets as far as I know so
you can't just drill a hole for the cow magnet but must find some way of
mounting the rectangular neodymium magnet. Perhaps drill a series of holes and then
use a chisel to knock out the rest of the wood forming a rectangular hole.
The force should also depend on the rate at which the area is changing so the
faster it swings, the better? So start the swing at least twice as high as
the position of the secondary coil???
I have never done this experiment but it sounds really neat. I did not see a
response to the father who wrote the orginal email in 1998.
R. Clements
rclem616@aol.com

This archive was generated by hypermail 2.1.3 : Mon Apr 24 2006 - 11:34:51 PDT