Before analyzing what it is an alternator we are going to see how we can obtain a f.e.m with the induction.
Experimentally to make current we have to move a magnet around a coil forexample. If the coil or the magnet are at rest there will not have induce corrent. So we should modify one element .
The magnet is moving so we can see how the galvanometer shows some current.
Someimportant laws are the Faraday’s law and the Lenz’s law. The last one comes from the Faraday’s law.
Faraday’s law: E=-dΦmdt siendo ∅m=BAcosθ E=Emáxsinθ
The “-“ in theFaraday’s equation is got for the Lenz’s law ,that say:”The induced e.m.f is in such a direction as to oppose, or tend to oppose the change that produces it.
An alternator simple is based in this twolaw’s.It’s represented like that:
In that generator AC the coil(In these case one), is moving while the magnet is at rest.
The change of the magnetic flux induce a e.m.f.
When the vector n(perpendicular to the surface) is paralell to the magnetic field B the magnetic flux is maximum and the ℰ=0.
When the vector n (perpendicular to the surface) is perpendicular to the magneticfield B the f.e.m is maximum and the ∅m=0.
The Bind (the inducted field) will be in the same sense of the B if the magnetic flux is reduced and in the opposite if it is increased.
In the real lifethere is a relationship between this alternator and an alternator’s car.
Every car has a alternator inside. This alternator is an electromechanical device that converts mechanical energy toelectrical energy in the form of alternating current. This electric energy will be stored in the battery of the car.
Alternator with one wire.
An real car’s alternator could be like that. In this casewill be a coil with N spires.
The principals components are:
-The rotor(inductor) that it is a rotating magnetic core.
-The stator(induced), that there have some spires at rest.