Homemade Franklin Bells

This device is extremly simple to build. All you need are:

Two coke cans

Some wire

A straw or pen

A piece of thread

A high voltage source (Van de Graaff Generator or a TV screen)

CONSTRUCTION:

The picture is self explanatory. Except that the circle is a soft drink can tab. It is tied to a straw/pen using a cotton string.

SIMPLE EXPLANATION:

When you turn on the high voltage source, the can connected to it (let's refer to it as the right can) gets charged . The charges on the surface of the can want to travel to the ground, so they do it via the tab. The charges attract the tab, "hop" on and "swing" to the left can. Then they go to the ground. This leaves the tab neutral again so it swings back to the negatively charged right can...

Sometimes, when the voltage is high enough, instead of the metal tab swinging, a spark will just jump between the cans and metal tab.