How an electric generator works

How An Electric Generator Works An electric generator is a device used to convert mechanical energy into electrical energy.

How an electric generator works

Particularly, if a coil is spinning in a magnetic field, the two sides of the coil move in opposite directions, and the voltages induced in each side add.

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Originally this relationship has been found experimentally. It is referred to as Faraday's law. The minus sign here is due to what is known as Lenz law, which states that the direction of the emf is such that the field from the induced current opposes the change in the flux which produces this emf.

Lenz law is explained by the conservation of energy. For clarity the above animation shows a single rectangular wire loop.


Normally, there is an armature with a set of windings on an iron core. If an external circuit is connected to these terminals, electric current will flow through this circuit, resulting in energy being delivered to the load.

The higher current, the larger force must be applied to the armature to keep it from slowing down. Thus, the rotational mechanical energy is converted into electrical energy.

If you use a commutator, such system is called dynamo. Its operation is similar as described above, except the output voltage becomes pulsating unipolar.

The above animation illustrates the basic concepts of generator operation. In reality, such configuration is seldom used except as an educational project. In practice, the mechanical energy that rotates the coil is produced by turbines or engines called prime movers.

Interactive Electric Generator

In small AC generators for residential use the prime mover is a rotary internal-combustion engine. Note that the production of the voltage depends only on the relative motion between the conductor and the magnetic field.

EMF is induced by the same physics law whether the magnetic field moves past a stationary coil, or a coil moves through a stationary field. Its terminals are connected to slip rings, which are in contact with two brushes. The main disadvantage of revolving power-producing armature is the load current has to flow via a slip rings and brushes, which wear out with use.

Today's AC gensets normally have spinning field and a stationary armature. This armature comprises of a set of coils that form a cylinder.

Portable Generators How They Work | Briggs & Stratton

Also, in practice, the magnetic flux is usually induced by an electromagnet rather than a permanent magnet. An electromagnet consists of so called field coils mounted on an iron core.

A current flow in these coils may be driven either from an external source or from the system's own armature.

How an electric generator works

Many modern AC sources are self-excited: For the operation theory of practical residential generators see this tutorial. It explains how does self excitation work and how to do "field flashing" when a genset does not start.So how do wind turbines make electricity?

Simply stated, a wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity.

The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. In Michael Faraday's generator, coils of copper wire rotating between the poles of a magnet produce a steady current of electricity.

One way to rotate the disk is to crank it by hand, but this isn't a practical way to make electricity. How Generators Work How An Electric Generator Works.

An electric generator is a device used to convert mechanical energy into electrical energy.. The generator is based on the principle of "electromagnetic induction" discovered in by Michael Faraday, a British scientist.

When the water moves across the turbine, it spins, rotating the shaft and, in turn, rotating the copper coils of the generator. As the copper coils spin within the magnets, electricity is produced.

Power lines connected to the generator carry electricity from the power plant to homes and businesses. An electric generator is a device that produces electricity from mechanical energy.

The mechanical energy for generators in turn is converted from chemical or nuclear energy in various types of fuel, or obtained from renewable sources, such as wind or falling water.

A generator using permanent magnets (PMs) is sometimes called a magneto, or permanent magnet synchronous generators (PMSMs).

Armature: The power-producing component of an electrical machine.

How an electric generator works

In a generator, alternator, or dynamo the armature windings generate the electric current, which provides power to an external circuit.

Electric generator - Wikipedia