MAKE presents: The Inductor

The deceptively simple wire coil that proves incredibly useful in the world of electronics — the inductor’s ability to store energy in an electromagnetic field is the key to making transformers, electromagnets, and many more components. It truly is an awesome device!

For questions, suggestions, and more info –
http://blog.makezine.com/archive/2009/11/make_presents_the_inductor.html