Magnet wire

Bottle Radio

[youtube http://www.youtube.com/watch?v=9VqVaFMQd2o?wmode=opaque&w=620&h=349] Crystal radio technology has been around for many years. This “bottle radio” take on a crystal radio requires no power source, operates on the power from radio waves, and receives signal from a long wire antenna. As radio stations slowly move away from the AM band, the “window of opportunity” to experience this […]

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Electromagnetic Aluminum Levitator

About 13 years ago I learned of some military research into a satellite- and missile-defense device that would propel projectiles using Lenz’s law, which governs the direction of electrical current induced by a changing magnetic field. I decided to make a little gadget based on the same principle for my kids, to get them interested […]

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Treasure Finder

Who hasn’t dreamed about owning their own metal detector and searching for buried treasure, or at least a few dropped coins? In this project, we will build a metal detector based on a dual oscillator circuit. One oscillator is fixed, and the other varies depending upon the proximity of metal objects. The beat frequency between […]

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