OK folks, this one is scary, but that’s part of the thrill. The voltage is high but the current is so low it probably won’t hurt you, much like a really good spark from walking on a carpet. It might also ruin the TV. I know, I’ve done that before. But hey, what else can you do with an old CRT television? It won’t bring $5 at the garage sale.
You will need to set up two cans, one wired to ground and one wired to a sheet of aluminum foil which is taped over the TV screen. An LCD TV will not work; it does not produce the high voltage needed.
Like most of these, getting it adjusted so it works right is the tricky part. Once it works the pendulum will oscillate back and forth REALLY FAST and ring the bells. The process of getting it adjusted will quite possibly cause a few harmless sparks to your own self, much to the great glee of the children nearby. A little showmanship here can’t hurt.
Benjamin Franklin actually made a similar device that he used to let him know that there was enough lightning outside to begin his experiments. He got very lucky though with his experiments. When other scientists tried to duplicate his work a number of them got electrocuted by the lightning. Your version will be much safer.
Look at the pictures. Search the internet for images, videos and instructions for “Franklin’s Bell” or “Franklin Bells”. Look at this example of instructions, then build your own. http://sci-toys.com/scitoys/scitoys/electro/electro4.html And yes, there even is a version using electric flyswatters for the voltage source.
My favorite image of this is at http://vimeo.com/51183310