Download Linear Generator Project

Linear Generator Project
Flip Flop PD 2012
Scientific Background:
When Michael Faraday made his discovery of electromagnetic induction in 1831, he
hypothesized that a changing magnetic field is necessary to induce a current in a nearby circuit.
To test his hypothesis he made a coil by wrapping a paper cylinder with wire. He connected the
coil to a galvanometer, and then moved a magnet back and forth inside the cylinder. The same
principle is being investigated in this project.
Electromagnetic induction is the process of inducing voltage by changing the magnetic field in a
coil of wire. According to Faraday’s Law, the induced voltage in a coil is proportional to the
number of loops times the rate at which the magnetic field changes within those loops. More
voltage is induced if there are more loops and if the relative motion between the magnet and
the coil is faster.
Materials:
1 plastic dowel rod (12 inches long)
Spools of enamel coated magnet wire (22, 26 or 30 gauge)
1 pc LED light bulb
1 pc cylindrical magnet
2 pc Alligator clips (optional)
Jumper wires(optional)
Multi tester
File or sandpaper
1 roll electrical tape/masking tape
Rubber stoppers / cork stoppers
Pablico, J. & Quisido, G., Flip Flip PD 2011, East Baton Rouge Parish School System
Procedure:
To Prepare the Linear Generator
1. Measure 10 cm on the middle of the plastic dowel rod and mark the boundaries using a masking
tape or electrical tape. Leaving a lead of 10 cm, begin wrapping the copper wire around the
middle of the rod.
2. Keep wrapping until at least 1000 turns are made. When the first spool ends and more wire is
needed, remove the enamel insulation from the tip, exposing about 1 cm of bare wire. A file or
sandpaper may be used to scrape off the enamel of the wire.
3. Take the second spool of wire, remove the insulation on the lead, and connect it to the end of
the first spool. Make sure both leads are completely bare. Secure the connection with an
electrical tape.
4. Keep wrapping, connecting the next spool when the previous spool ends, until at least 1000
turns are made. Leave the last 10 cm of the wire to be the other lead. More spools may be used
if desired.
5. Remove the insulation on both leads of the copper coil and connect each to an LED light, or to a
jumper wire that connects to a multi-tester .
6. After the coil is made, place the cylindrical magnet inside the pipe and seal each end with a
rubber stopper or cork stopper.
Demonstration Procedure:
1.
2.
3.
4.
5.
Connect the ends of the coil to a multi-tester and set the dial to read volts of alternating current.
Shake the linear generator.
Measure the voltage generated by the linear generator.
Connect the linear generator to a LED light bulb.
Observe the LED light up.
How it works:
When the device is shaken back and forth, the magnet oscillates through the coil and induces an electric
current. When there’s relative motion between a wire and a magnetic field, work is done on the charges
and an electromotive force (emf, measured in volts) is induced in the wire, causing the electrons
(charges) to flow.
(Originally submitted as a McKinley High School Project for Earth Day Science Challenge 2011)
Pablico, J. & Quisido, G., Flip Flip PD 2011, East Baton Rouge Parish School System