How to Build an Electric Generator With a Wire & a Magnet

Even though creating a generator -- a device that can convert motion into electricity -- sounds like a daunting task, it is a simple device that you can make at home. You need no special tools, and little more than a magnet and a single piece of wire. Your homemade generator will be able to light a small bulb and show current and voltage on a multimeter. It is well suited for science projects.

Things You'll Need

• Strip of thick cardboard 9 inches long, 4 inches wide
• X-Acto knife
• Glue
• Bar magnet made out of ceramic or neodymium, 2 inches long (See References 2 & 3)
• Ruler
• Square of wood, 1 1/2 inches on each side and 1/8-inch thick
• Drill
• Hacksaw
• 3 dowels, 1/4 inches in diameter, 2 inches long
• Strip of wood 1/4 inches wide, 2 inches long
• 200 feet of 30 gauge magnet wire
• Hammer
• Small nails
• Electrical tape
• Emery board
• Bulb holder sized to fit bulb
• ½ volt light bulb (See Reference 1)

Instructions

1. Fold the cardboard into four equal sections. Cut a 1/2 inch hole in the center of the first section and the second after it, using the X-Acto knife. Glue one end of the cardboard to the other, so that it forms a box 4 inches tall and 2 1/4 inches across. Allow the glue to dry.

2. Measure the width and height of your bar magnet. Using those dimensions as a guide, cut a rectangular hole in the center of the small wooden square. Start the hole with the drill and then cut it to size with the hacksaw.

3. Cut a 1/8-inch wide, 1/2-inch deep notch in one end of two of the dowels. Use the hacksaw.

4. Nail one end of the strip of wood to the unnotched end of one of the notched dowels. Nail the small dowel to the end of that. This will form the handle of the generator.

5. Tape one end of the wire to one corner of the box, in the middle. Leave several inches trailing from it. Wind the wire around the box, staying as close to the middle as possible. Tape the coil in place when done to prevent it from unwinding. Leave several inches of wire trailing away from that end, too.

6. Stick the notched end of the dowel with the handle on it through one of the holes in the box. You may need to push aside some of the loops of wire to get it there.

7. Stick the bar magnet through the hole in the square of wood. Glue the square of wood into the notch of the dowel sticking into the box. Insert the other notched dowel into the other hole and glue the square of wood into that notch as well.

8. Sand the enamel insulation off the ends of the coil of wire using the emery board. Screw these ends of wire into the terminals of the bulb holder. Screw the bulb into the holder. Set the box down so that the handle is on its side. When you turn the handle fast enough, the bulb will light up.

References

• University of North Carolina Wilmington: Ultra-Simple Electric Generator
• University of Arizona PULSE: Home-Made Generator
• Absolute Astronomy: Neodymium Magnet

Resources

• Georgia State University Hyperphysics: AC Motors and Generators