Electricity has always been a phenomenon of particular interest to me. When I was a kid, I would linger before the fridge and stare with questioning eyes at the light bulb that showed me the fridge’s contents even in the dead of night. I would switch on the TV and, while I was watching ridiculous Saturday morning cartoons, would wonder just what it was that made it possible for me to watch these pictures on my television. I would shock myself with nine-volt batteries and wonder what had hurt me, and drive my remote control cars around the neighborhood wondering what it was that made those wheels turn. Indeed, throughout my years I have always marveled at the purpose and the properties of electricity, so it was no wonder that my seventh grade science project involved a steam-powered electrical generator.
The concept of this project was at first somewhat difficult for me to grasp. I learned that a magnet, when spun, would create an electrical current as a result of its rapidly changing magnetic field. Since the goal of my experiment was to create electricity, a powerful magnet was an integral part of my design. Next, if spinning this magic created a rapidly changing electromagnetic field that generated electricity, I would need something to collect this electricity without allowing it to escape into the atmosphere. The most conducive material I could find was copper, and so I found some thin copper wire capable of conducting electricity.
So far, the materials for my project include a powerful magnet and copper wire, but we are far from done. In order to spin the magnet fast enough to create electricity, we need to build what’s called a turbine, and we need to spin the turbine relatively quickly. For the turbine’s shaft I used a simple wooden dowel, and for the propellers that would eventually be spun by steam, I used a sturdy aluminum that I collected from cut up soda cans. After we have the turbine, we need something to turn it.
The steam that turns the turbine comes from superheating water to the point where the pressure from expanding steam in constricting pipes blasts through an arranged opening near the turbine and spins the aluminum propellers, and then the magnet. In order to heat the water, we need a reservoir of water kept in a metal container capable of conducting great heat. Again, I found copper to be a sufficiently conducive material, and so built the reservoir of a sturdy copper. Extending from the top of the reservoir needs to be a length of narrow copper pipe-not so long that the steam cools down before it gets to the end, but not so short that the steam comes blasting out without being focused on turning the turbine.
I’ve listed a lot of materials needed for this experiment, so I’ll revisit the list here. What you’re going to need is-
A powerful magnet
A length of thin copper wire
A wooden dowel
Aluminum soda cans cut up into the shape of propellers
A copper reservoir
A length of narrow copper pipe
A powerful heat source (such as a Bunsen burner or powerful hot plate)
Once you have collected all of these objects, begin to assemble them in this way.
1) Connect the length of narrow copper pipe to the top of the reservoir. If you connect it to the bottom, only water will pour forth- if you connect it to the top, then only steam will funnel through the piping to turn the turbine.
2) Place the aluminum propellers connected to the wooden dowel at the entrance to the piping emerging from the top of the reservoir, so it can be turned by the steam.
3) Fasten the magnet to the other end of the wooden dowel where it will spin at the same speed of the propellers.
4) Surround the magnet with a coil of copper wire that will pick up the electricity thrown off by the rapidly changing magnetic current. The copper wire should not be touching the magnet, as this will restrict movement, but it should be coiled close enough to conduct the electricity created by it.
5) run a part of the copper wire to a light bulb, or whatever you want to use to test the current of electricity.
6) Now that your experiment is set up, use the Bunsen burner to vaporize the water in the copper reservoir. The pressure of the rising steam should turn the aluminum propellers as it escapes from the piping, thus turning the wooden down, which in turn will spin the magnet attached to its end. The coil of copper wire will pick up the electrons thrown off by the magnet’s rapidly changing magnetic field and will direct them to the light bulb or whatever is fastened at the wire’s other end. If your experiment is a success, the light bulb will light!
Imagine being the only one at the science fair with enough ingenuity to construct a steam-powered generator. You will be the envy of your classmates and undoubtedly receive plenty of extra credit for your efforts- something you could never have enough of in seventh grade!