How an Electric Generator Works:
Electromagnetic Induction
In 1831, “Michael Faraday discovered that a voltage would be generated across a length of wire if that wire was exposed to a perpendicular magnetic field flux of changing intensity.” This is called Faraday’s Law of Induction. https://www.allaboutcircuits.com/textbook/direct-current/chpt-14/electromagnetic-induction/
Faraday’s Law of Induction
“Electromagnetic Induction is the process of using magnetic fields to produce voltage, and in a closed circuit, a current.”
http://www.electronics-tutorials.ws/electromagnetism/electromagnetic-induction.html
How It Works
When a continuous circuit of conductive wire surrounds a magnetic field, if the magnetic field moves in relationship to the wire, this movement generates an electric charge called “Voltage” in the wire. The faster the magnetic field moves, the larger the voltage becomes. If you turn the magnet in a circle relative to the wire, this forces electric charge to move in a rapid circle through the wire.
1. If your circuit of wire is closed, the charge flows around and around through the wire. If you interrupt the circuit by breaking the wire, the charge hits a dead end and doesn’t flow. 2. If you add something that can use power, like a lightbulb, in line with the circuit, the flowing charge will power the lightbulb. http://amasci.com/coilgen/generator_2.html
How to Build an Electric Generator | Adams County Public Library adamscolibrary.org/stem
Why does the current pulse?
A magnet has a North and South pole. One pole pushes the electric force in the wire, and one pole pulls the electric force. This means that when you turn the magnet in relationship to the wire, it is pushing and pulling the current in the wire.
Our project generates Alternating Current, which “pulses” rather than “flows.” Electric powered devices and wall outlets use “DC” Direct Current, which flows continuously.
The Factors in AC Generator Power
How to increase the charge generated by our hand generator?
1. Longer wire – more continuous coils of wire in the circuit. This gives more material to provide electrons to carry the charge. 2. Increase the speed at which you move the magnet. 3. Increase the strength of the magnetic field (use a larger or more powerful magnet).
Understand Current, Voltage, and Power
1. There are two types of charge: attract and repel 2. Conductors and Insulators: behavior of the electrons. Are they free to flow? Or are they held tightly to the molecules of the material? What are some examples of conductors and insulators? 3. Current is the flow of charge through an electric conductor 4. Voltage is the change in energy experienced in a charge 5. Power is the rate at which energy is transferred over time https://www.khanacademy.org/science/physics/circuits-topic/circuits-resistance/a/ee-voltage-and- current
Safety
Keep the powerful magnets away from phones, TVs, computers, and other electronic devices! Computers store information on very sensitive silicon circuits which remembers the magnetic charge of individual electrons. A magnet can permanently disrupt the computer’s memory.
Do not touch the ends of the electric coil to batteries or wall outlets! Both batteries and wall outlets contain much more powerful electric current. Directing it through the generator can result in a severe shock and other dangerous effects.
How to Build an Electric Generator | Adams County Public Library adamscolibrary.org/stem