this post was submitted on 01 Jul 2023
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ELI5
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Explain it to me like I am 5. Everybody should know what this is about.
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@AppleMango
@D-ISS-O-CIA-TED@kbin.social
AC is actually a little easier to explain.
Imagine you're holding each end of a rope that is looped around a pulley. When you pull on the rope with one hand, your other hand goes in the opposite direction and the pulley turns a little bit. You've transfered a little bit of work to the pulley, which can be used to do other things. But "you" have only moved a little bit. You pull your stretched hand in, and you other hand goes out and the pulley does a little more work. Now do this movement 60 times a second (50 in some parts of the world), and you've just discovered alternating current electricity. You don't have to move much in order to send energy over long distances, which is one of the advantages of AC over DC.
To add to this, imagine that pulley on the end is connected to another pulley through a few gears. When it spins one way, it turns the last pulley one way. When it spins the other, it meshes with another gear to turn the last pulley the same way.
You've converted AC current into DC current, which you can use to drive a motor in one direction. This gearing is usually done via a series of diodes.
I could visualize your description of this, but ONLY because I recalled this great little Steve Mould video where he talks about a really neat toy called Spintronics. It teaches electricity through the analogy of gears, ratchets, and pulleys of a "mechanical circuit."
So in an AC current the electrons are just jiggling back and forth? How far do they move through a wire, I'd imagine they jump like a few meters back and forth if it's only 50/60 times per second.
It's not really the electrons moving. It's the electromagnetic field potential that's moving. The rope is that field. And the distance it moves isn't measured in meters, but in volts. In most cases, around 240 volts (more or less...but that's a whole other discussion).
A lot of this is hard to wrap your head around because you can't physically see these forces, only measure them with instruments. We'll dive a little deeper while still trying to keep the rope metaphor going.
Imagine each electron in a wire as stationary, and all standing in a line next to each other all the way down the wire, each connected to its neighbour by a loop of rope. If you turn one of these electrons, it causes the one beside it to turn, which causes its neighbour to turn, etc all the way down. Our pulley is attached to one of these electrons. You pull the rope one way, it turns the pulley, which turns the first electron, which transfers that energy all the way down the line. How far you pull in one draw is the voltage. How hard you pull is the amperage.
This is the basis of a generator. A magnet (our pulley) is passed over a coil of wire, which induces an electromagnetic field (our rope) in the wire. It makes the electrons "turn", and sends that energy down the entire length of the wire. Nothing really moves except for the electromagnetic field.