Magnet wire

Bottle Radio

Bottle Radio

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 remarkable technology […]

Mendocino Motor

Mendocino Motor

See photons turned into motion with this solar-powered, magnetically levitating electric motor.

Wind Your Own Guitar Pickups

Wind Your Own Guitar Pickups

The brilliant Meara O’Reilly describes how to wind your own electromagnetic guitar pickups on sewing machine bobbins.

Electromagnetic Aluminum Levitator

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 […]

Treasure Finder

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 […]

Jam Jar Jet

Jam Jar Jet

Build a simple pulsejet engine in an afternoon.