Which is a better alternator or generator?

The basic principle of working for both alternator and generator is the same. They both worked on the electromagnetic law of Faraday. The generator has the ability to produce AC as well as DC current. The alternator has the ability to produce only AC current. So in terms of the type of current generation generator is better than alternation as it produces two types of current.

Basic Difference Between Generator and Alternator

There is an architectural difference between both the devices and the difference is related to the armature and field. In the case of the generator, the field is stationary

while the armature rotates. In the case of the alternator, the things are opposite this means that the field rotates while the armature is stationary. Generators produce the alternating current naturally. The direction of the current changes with every half rotation of the motor. As the motor changes the direction the current direction automatically changes. So this is natural for the generator to produce the AC type of current. The commutator is needed if you want to produce the DC current. So the commutator is introduced with the wires that carry the output current. This will turn the output into the Direct current although the input is the Alternative current.

[/su_heading]The Top  Differences that Occur in the alternator and generator[/su_heading]

These are the top differences that hold between the Alternator and generator and separate them both from each other.

Type of the Current

The major difference is the output of the current. In the case of the generator, both types of currents can be obtained as the output. The AC is the only output option that can be obtained as a current from the alternator.

Magnetic field

The alternative has a single type of magnetic field. While the generator has two types of magnetic fields one is for low voltage generation and the other is for high voltage generation.

The magnetic field in the alternator is rotating, while the magnetic field in the generator is stationary.

Stator and the Rotor

Next is the point from where the generator and the alternator take the input supply. In the case of the generator, the supply is provided by the Rotor. The stator is the initial supply provider for the alternator. In the case of the generator, this supply is provided through the rotor.


The armature is stationary in the alternator. While in the generator this is rotatory.

EMF OutPut

There is a difference in output EMF in both devices. In the case of the alternator, this EMF output is alternating. In the case of the generator, this Output becomes static. Moreover, the alternator will not charge the dead battery while the generator will charge it

RPM (Rotation Per Minute)

The generator has a narrow range in comparison to the alternator if we compare the rotation per minute of both types of devices. The output is higher in the case of the alternator while in the case of the generator this is on the lower side.

The Need of the Polarization

The generator needs to be polarized once it is installed in its required place. As far as the polarization of the alternator is concerned it is not required. So this is another difference that occurs between the generator and the alternator.

On-Demand Voltage generation

This is a type of activity that occurs in power generation machines. This is a type of functionality that is not available in the case of the generator. The generator produces voltage all the time. While in the case of the alternator the voltage is produced only when it is needed by the system.

Alternator vs generator car

In the case of cars, this is interesting to know that the alternator is used in the car instead of the generator. This is really an interesting factor that although the appliances in the car run on the DC type of the current. But the manufacturer of the cars preferably to install alternator in the car. The car has a functionality through which the AC type of the current is converted into a DC type of the current.

Now the question stays at its place and the question is that if everything in the car runs in the DC then what is the fun in producing the AC type of current in the car. The answer to this question is that the alternator is more efficient in converting the motion energy into electricity. On the other hand, the generators are not capable enough in this regard.

Alternator vs generator aircraft

Aircraft needs power generation devices. Alternator and generator both are used in the aircraft for power generation. Majority of modern aircraft use the alternator instead of the generator. There was a time when generators were used in aircraft. With the passage of time the number of aircrafts that use alternator instead of generator is increasing rapidly.

Generators and alternators both have their own advantages and disadvantages while used in the aircraft.

The alternator will not be able to produce the current for the dead battery of the aircraft. On the other hand, The generator does possess the quality even to charge the dead battery. The alternator has the advantage of being lightweight and it can convert the motion enter of electricity more efficiently.

Final Words
The alternator and generator both have their own advantages and disadvantages. The good thing is that these advantages and disadvantages are circumstantial. This means that in some certain circumstances The generator has an advantage over the alternator and in other circumstances, The alternator has an advantage over the generators. In the automobile industry alternators have an advantage over generators. This is the reason that more and more automobile and even aircraft manufacturers prefer to use alternators instead of generators. On the other hand, if you want to produce electricity on a large scale. Then in this case the preferred device will be a generator. The generator has a clear and outstanding advantage over the alternator in these terms.