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DC and AC generators (1 Viewer)

Ted_

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Jun 3, 2017
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2018
Can someone simply explain to me how DC and AC generators work?
I already know how the coil rotates, and the concept behind EMF and back EMF, and the factors that change the strength of the generators
Specifically, I'm a little confused on the split and slip rings, concerning their changing polarity, and how the coil is connected to it...
And I'm a little confused on direction of current in the coil... Do we read positive to negative, or negative to positive, and how do we determine it...?

I know it's a lot for one post, but I really appreciate anyone who replies.
Thanks in advance
 

YeetusMaximus

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Mar 27, 2018
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Current flows from high potential energy to low potential energy. This basically means the direction it goes in is from positive to negative

The point of a generator is to force a current to flow in a wire.

You need to know Faraday's law of induction which states that "a conductor in a changing magnetic field will experience a current through it". This means to generate a current, we just need to put a wire in a magnetic field that is constantly changing. To do this, we put the coil inside the magnetic ring. We must hand crank the generator to make the wire move. Because it is moving, the magnetic field strength flowing through the wire coil is always changing so therefore a current is induced.

Because the coil constantly changes the direction which it is pointed at, it generates AC electricity. If you know how split rings work in a motor, it is exactly the same in a generator. As the current always goes back and forth, everytime it goes one way, it will touch one half of the ring. When the current goes the other way, the wire will touch the other half. This means that the current always goes in one direction after going through the commutator. This is DC electricity

To make it come out as AC, a slip ring is actually 2 slip rings. Each end of the wire is attached to its own slip ring. Keep in mind that by "attached" I mean that they have brushes contacting them allowing them to actually rotate. Since they can keep continuous contact with their own ring, the electricity will come out as it was made, in AC
 

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