Generator is a machine that converts mechanical energy into electrical energy. It works based on principle of faraday law of electromagnetic induction. The faradays law states that whenever a conductor is placed in a varying magnetic field, EMF is induced and this induced EMF is equal to the rate of change of flux linkages. This EMF can be generated when there is either relative space or relative time variation between the conductor and magnetic field.
These are also called as alternators. It is the most important means of producing electrical power in many of the places since now days all the consumers are using AC. It works based on principle of the electromagnetic induction. These are of two types one is induction generator and other one is synchronous generator. The induction generator requires no separate DC excitation, regulator controls, frequency control or governor. This concept takes place when conductor coils turn in a magnetic field actuating a current and a voltage. The generators should run at a consistent speed to convey a stable AC voltage, even no load is accessible.
DC Generators: -
DC generator is typically found in off-grid applications. These generators give a seamless power supply directly into electric storage devices and DC power grids without novel equipment. The stored power is carries to loads through dc-ac converters. The DC generators could be controlled back to an unmoving speed as batteries tend to be stimulating to recover considerably more fuel.
Advantages of AC Generator -
These Generators are generally maintenance free, because of absence of brushes.
Easily step up and step down through transformers.
Transmission link size might be thinner because of step up feature
Size of the generator relatively smaller than DC machine
Losses are relatively less than DC machine
These Generator breakers are relatively smaller than DC breakers
Advantages of DC Generator - Mainly DC machines have the wide variety of operating characteristics which can be obtained by selection of the method of excitation of the field windings.
The output voltage can be smoothed by regularly arranging the coils around the armature .This leads to less fluctuations which is desirable for some steady state applications.
No shielding need for radiation so cable cost will be less as compared to AC
Thanks for watching
Doodle Science teaches you high school physics in a less boring way in almost no time!
Follow me: https://twitter.com/DoodleSci
You can support me at: https://patreon.com/doodlescience
When a current passes through a wire it produces a magnetic field. If you put this magnetic field in another magnetic field, it puts a force on the wire. This is known as the motor effect.
To determine the direction of the force you use a handy trick called Flemming's left hand rule. The way this works is by taking your left hand and making this shape with it. You then assign your first finger to the direction of the magnetic field, which is always north to south, your second finger to the direction of the current, and your thumb to the direction of the force.
For example, in this case, Flemming's left hand rule states that the force would act in this direction.
A simple electric motor works using this fact. It works by looping a coil of wire around to two electrical contacts inside a magnetic field. This causes one side of the wire to move up and the other part to move down, which causes the whole thing to spin. It is attached to something called a split ring commutator which is a clever way of swapping the contacts every half turn to keep it moving in the same direction. You can make the motor go faster by either increasing the current or by using a stronger magnetic field.
So next time you use your hair dryer, you’ll know something more about the way it spins.
2. CGP GCSE Physics AQA Revision Guide.