Tuesday, April 21, 2009

Wind Power Unit Study - Day 6: Building an Electric Generator (for kids)

We've been gradually working our way through the parts of a wind turbine. Today, we took a look at the generator. Some wind turbines are used to generate mechanical energy, rather than electrical energy. Since we had already done an experiment involving the load lifting capacity of various rotor designs, today, we focused in on generating electricity.

I was very happy to find the design for a very simple electric generator at www.amasci.com/amateur/coilgen.html . I was even happier about it, when I read that all of the necessary parts could be purchased for a minimal sum from Radio Shack. All that is needed is a spool of very thin copper wire, a nail, some cardboard, a very small AC light bulb, and four two inch ceramic magnets.

• The cardboard is formed into a small box.

• A nail is punched through the center of the box.

• The magnets are stuck together and positioned, two on each side of the nail, inside the box.

• The wire is wrapped 200 to 300 times around the outside of the box.

• A small light bulb is attached to ends of the wire.

• The children spin the nail, and thereby the magnets.

• The light bulb lights up!

I'm never too impressed by tiny glowing light bulbs, but it did fit in nicely with our study. Of course, when I gleefully yelled, "I have created electricity!", the children completely missed my Tom Hanks, Cast Away, reference. It's always nice to have an experiment actually work the way it's supposed to though.

At this point it would be fun to finish off the gear box for our paper wind turbine tower ( see www.windpower.org/en/kids/teacher/turbkit.pdf), and attach it to our generator to test and see how much power we could generate - but that might be an experiment better saved for the high school years. Besides, we just received word that the grandparents are going to be paying us a visit - which means another holiday (or maybe we can get some art lessons out of Grandma).

It's great to be a homeschooler!