The Rotating Tiger Cheese Box

       Analog Dial        Making The Top Making The Base      

-- mouse-over for controls --
Given to Matthew Knoebel, A.K.A "Rocket Boy". December, 2012

How does it work?

Inside the top (rotating part) are eight permanent
magnets, evenly spaced. The poles of the magnets
all face the same direction.
Inside the base are an electromagnet, a magnetic reed switch and a battery. The pole of the electromagnet is the same as the poles of the permanent magnets in the top, so that when it is on it will oppose those magnets and push them away.

The active component is the magnetic reed switch, invented at Bell Telephone Laboratories in 1936 by W. B. Ellwood. The reed switch is normally open but closes in the presence of a magnetic field. Two types are shown here.
The position of the reed switch is critical. It controls
the timing, the way an old fashioned distributer in
a car controlled the spark to the spark plugs. There
is a capacitor across the switch. More on that later.

In operation...
As a magnet in the top cheese box approaches the reed switch in the bottom box, the magnetic flux closes the reed switch, activating the electromagnet. The electromagnet kicks the permanent magnet away and the reed switch opens. The next magnet swings by and the process is repeated. This happens over and over, causing the top cheese box to spin. The reed switch closes eight times for every time the cheese box spins once.

NEXT, how it was made and tips for making your own.