how do electric dynamos create electricity simply from a few magnets and copper wiring?
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Because electricity and magnetism are tied together through a process called “induction”.
When a wire has electricity through it, it “induces” a magnetic field around the wire. This is how electromagnets work, lining up the wire in a certain way to amplify the magnetic field created when you run electricity through it.
And, the opposite is true, the same way moving electrons can create a magnetic field, a moving magnetic field and cause electrons to move.
That’s how a dynamo works, instead of electric wire creating a magnetic field, you take a magnet, Surround it by a coil of wire, and then spin the magnet which causes its magnetic field to spin which causes electrons in the wire to start moving, generating electricity.
First some physics facts.
1, Magnetic force can be used to generate kinetic energy (moving the magnet closer to metallic object),
2, Magnetic forces wrap itself around an electrical current.
3, Electric current is a flow of charged particles from one atom to another.
4, Particles start to move when they cut through a magnetic current.
Electric generators work by putting all these things together. First you have to put the initial “energy” into the system. This can be done by moving a crank yourself or having a steam turbine turn it by burning coal. This crank is then connected to a magnet which rotates inside a copper coil or vice versa. This rotation causes a continuous “cutting through” a magnetic field which pushes electrons from their atoms inside the copper wire. This generates an electrical current that flows from point A to a point B along the copper wire.
You don’t even need a “magnet”, just a magnetic field… which can be created by running electricity through some coils of wire. And then if you move other coils of wire through the field made by the first, current will flow.
Alternatively, if you run current through the second coils of wire, it will push against the magnetic field and create movement!
ELI5 version – move copper through an magnetic field = electricity.
That’s all generators are doing.
There are three things involved, movement, flow of electricity and magnetic field and they are described by what is called a Lorentz force
If you move a wire through magnetic field, you will be able to measure potential difference on its ends. What happens is (very oversimplified) as you move the electrons in wire at right angle to the magnetic field. The electron will begin to move along the wire. Thus making more of them on one end and less on another. This difference means voltage, or as you put it electricity.
And in reverse, if you push electricity through magnetic field (run electricity at right angle to the direction of magnetic field) the wire it is running through will be pushed away.
Electric motor uses the second effect, dynamo uses the first.
Dynamo rotates magnets in the middle of the coils of wire, since you now have wire moving in the magnetic field (even though it is the magnets moving), you will get voltage on the ends of the wire.
If we were to be more accurate we would be talking about force on point charges (electrons) moving in electric and magnetic fields.
A magnet creates a force field, of sorts. When it’s just sitting there, the field is stable and nothing happens so far as the wire is concerned.
BUT when the magnet and wire change position relative to each other the shape and/or polarity of the field (as seen by the wire) changes, and the electrons in the wire go flying off trying to find a new stable condition, they want to be back to the part where (as far as they care) “nothing is happening”.
Electricity is produced by constantly changing the relationship between the magnet(s) and the coil of wire, in other words — forcing the electrons in the wire to constantly be chasing a steady state. If you imagine a bunch of electrons hanging out on a treadmill that’s turned off, they are just there enjoying the view. Turn the treadmill on and they all go racing off to find a treadmill that is off. They find the new treadmill, and you turn *that* treadmill on and the first one off…they switch back. They don’t want to be running, they want to chill.
You keep flip-flopping the relationship status of the wire and magnet, do it fast enough and you end up with a constant flow of electrons — also known as an electric current.
When magnets move past wires they pull on the electrons in the wires making electricity. Move the magnets fast and put lots of wires in the same place and you can make lots of electricity. A coil puts the same wire in the same place lots of times so you don’t need lots of wires in the same place. Spinning the magnets in a circle lets you keep re-using the same magnets over and over instead of them flying out one end of the machine.
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