What Is Alternator? | What Is Generator? | AC VS DC | What to Look Out for in Generator | Alternator VS Generator

Alternator VS Generator

What Is Alternator?

What Is Alternator

Alternators are machines that convert mechanical energy into electrical energy to generate alternating currents. Hence, it is called an AC generator or synchronous generator.

In an alternator, electricity is generated when a magnetic field moves inside the coil’s winding. There are different types of alternators depending on the application and design.

Some of these are the marine-type alternator, automotive-type alternator, diesel-electric locomotive type alternator, and brushless type alternator. Alternators are conserving energy by using only the required energy.

Also, Read: What Are Resistors? | Resistance with a Sinusoidal Supply | What Is Impedance? | Resistance VS Impedance

What Is Generator?

What Is Generator

Electric generators are machines that provide electricity when there is no power supply from the power grid. The armature or winding of the wire in a generator rotates within a fixed magnetic field and hence generates electricity.

Thus, industrial generators are often primarily useful for supplying power backup for electrical equipment in the home or office.

Also, this power supply will do all the work of supplying from the grid. This power source is always useful in the scenario where power grid supply is not possible such as in mining and farming operations.

This also applies during new development and construction locations. Some electric generators are small as well as portable. But there are also large generators, which need proper and permanent installations.

Industrial generators are very powerful and hence able to maintain full power to manufacturing facilities etc.

There are a few types of generators such as diesel generators, natural gas generators, propane generators, and bi-fuel generators.

Also, Read: What Is a Synchronous Generator? | What Is an Induction Generator? | Induction Generator VS Synchronous Generator



Alternators are types of generator that generates electrical energy in the form of alternating current (AC) from mechanical energy.

The ability to converts mechanical energy into electricity to charge your car’s battery under the hood makes them a common finding in the auto industry.

A current is created to deliver energy by the mechanical process of rotating the magnet without conversion to direct currents (DC).

This device only generates energy when needed, making them very efficient.

They can turn on or off when the battery needs to be recharged and, therefore, your car will not die if run for extended periods of time.

One telltale sign of a bad alternator is that your car’s battery is drained if the car is still running. This means that the device is not charging the battery.

In general, an alternator is a more rapid version of a generator that wastes less energy because it can reduce the amount of power needed.

They cannot charge a dead battery completely as this can lead to a fire and cause more damage.

Also, Read: What Is Head of a Pump? | How Does a Sump Pump Work? | Types of High Head Sump Pump | Advantages of Sump Pump | Disadvantages of Sump Pump



On the other hand, generators generate electricals energy from mechanical energy as wells. The process is similar to that of alternators, but generators can provide either’s AC or DC.

Generators consist of rotors, which are made up of coiled wires.

These coiled wires spin and cause electricity to build up while the magnetic field surrounding them remains constant.

As a result, magnetic fields are created &, in turn, generates the amount of energy needed to rotate the armature.

The magnetic field of the alternator always rotates inside the stator. This is in comparison to generators, which have a fixed magnetic field.

When the rotating chain of coils in an electric motor, also known as the armature, is stationary, it makes the rotor vulnerable to the production of (low) voltage excitation through the slip ring.

If more power is required, opt for a generator as it can generate a voltage across the appliance without stopping.

That being said, the generator can also be used to charge a completely depleted battery. In these aspects, we believe that as a power backup for homes & vehicles, generators are your best bet.

Generators are suitable for heavy-duty jobs as they have a constant output current and produce both AC and DC.

Also, Read: What Is Power Transformer? | Power Transformer Theory | Power Transformer Working Principle | Types of Power Transformer


AC vs DC.

It is easy to understand the differences between AC and DC. Batteries come with both a positive and a negative terminal, and charged electrons move from one end to the other as they move through a conductor.

As these charged electrons move, an electron pulse is generated when the alternating currents reverse the flow of these electrons.

In turn, these create energy currents that offer a smalls current of energy, making them useful for conserving electricity.

On the others side of the coin, direct currents supply a constant stream of electrons that flow in one direction.

Regulating alternating currents is needed to control the amount of energy produced by the source when a specific frequency is required.

Also, Read: What Is Thermal Pollution? | Causes of Thermal Pollution | Effects of Thermal Pollution | Solutions to Thermal Pollution


So, how does an alternator compare with a generator, & what are their main differences? On the one hand, the alternator produces AC electrical energy from mechanical energy.

In contrast, generators convert mechanical energy into both AC and DC electrical energy.

The alternator also has a dynamic magnetic field and rotations per minute (rpm) range, while the generator has a static one, where the armature winding spins and gives a small variation in its rpm range.

After this, alternators cannot ‘revive’ a completely drained battery, but a generator can.

However, the output current of an alternator is high as compared to a generator and is relatively very small in size.

Alternators can be used for small-scale power generation and charging cars, whereas generators are mainly used for large-scale power generation.

Lastly, the brush efficiency of alternators lasts longer than that of generators.

Also, Read: What Is Piston Ring? | How Is Piston Ring Installation Done? | Types and Functions of Piston Rings

What to Look Out for in Generator:

There is a wides range of options for you to chooses generators from. It can be difficult to distinguish the goods and bad of a generator, so if you’re ready to get a portable generator, whether it’s for leisure or emergencies, here are a few things you’ll want to pay attention to.

For starters, newer versions of the generator are equipped with push-button start.

It’s in comparison to the old pull-start we’re all familiar with. Thereafter, it is highly suggested to get one that comes with wheels to take its portability to the next level.

It takes a lot of effort to physically carry a generator and having wheels will add that touch of convenience you never needed.

It’s helpful to choose a generator that automatically shuts off when the oil level drops below a certain threshold, so protect yourself and your generator and make sure power is spread across multiple electrical outlets.

This helps to maximize the lifetime of the generator and also makes it a safe way to get the power you need.

Lastly, it never hurts to give yourself a few options, and some generators give you the option of using a source of fuel such as propane or natural gas.

You can even convert generators depends on what you need.

Also, Read: What Is Biomass? | Different Method of Biomass Conversion | Method of Biomass Conversion

Alternator VS Generator:

Sl. No. Differentiating Property Alternators Generators
1 Definition Alternators are a device that converts mechanical energy into AC electrical energy. Generators are mechanical devices that convert mechanical energy into AC or DC electricals energy.
2 Output Current An alternator always induces alternating currents. A generator can produce either alternating or directs currents.
3 Polarization After Installation Polarization is not required in the case of alternators. The generator needs to be polarized after installation.
4 Magnetic Field The magnetic fields are rotating insides the stators of an alternator. In the case of generators, the magnetic field is fixed or stationary where the armature’s winding rotates.
5 Armature Movement The armature of alternators is stationary. The armature of the generators is rotating.
6 Energy Efficiency Alternators are very efficient. The generator is considered less efficient.
7 Output Alternators have higher outputs than generators. The output of a generator is less as compared to an alternator.
8 Energy Conservation Alternators use only the required amount of energy & thus, it conserves more energy. Generators use up all the energy produced &; therefore, they conserve less energy.
9 Brush Efficiency The brushes of alternators last longer. The brushes of the generator run less than that of the alternator.
10 charging a dead Battery Alternators will never charge a dead battery Generators can be used to charge a dead battery.
11 Use Alternators are mainly used in the automobile industry as a charging system for batteries. The generator is widely used to produce electricity on a large scale.
12 input supply The alternators take input supply from the stator. The generator takes the input supplies from the rotor.
13 RPM (Rotations per Minute) range Alternators have a wide range of RPM. Generators have a short range of RPMs.
14 voltage Generation Alternators produce voltage only when needed. Generators produce voltages all the time.
15 Size An alternator is generally smaller in size. Generators are larger & require more space to fit.

These were the main differences between alternator and generator. These alternator and generator differences are a little deeper to help the students get a complete idea about them.

These detailed and advanced comparisons can help students to fully understand these related topics.

Also, Read: What Is Geothermal Energy? | Alternative Energy Sources | Which Are Main Techniques Used to Exploit Geothermal Energy?

Definition of an Alternator:

Asynchronous generators or alternators are a machine for converting mechanical power from a prime mover into AC electrical power at specific voltage & frequency.

A three-phase alternator is used because it has many advantages for distribution, generation, and transmission.

Large alternators are used in thermal, hydro, and nuclear power stations for bulk electricity generation. Magnetic poles of the rotors are excited by the direct field currents.

When the rotor rotates, the magnetic flux cuts the stator conductors & therefore induces an emf in them.

As the magnetic poles rotate N and S alternately, they induce an EMF and current in the armature conductor, which rotates first in a clockwise direction and then in a clockwise direction.

Thus, it generates alternating current.

Also, Read: What Is Solar Energy Used For? | What Is Good About Solar Energy? | Fun Facts About Solar Energy

Definition of Generator:

Generators convert mechanical energy into electricals energy or power. The working of the generator is based on the principle of Faraday’s laws of electromagnetic induction; that is, EMF is induced whenever the conductors cut the magnetic flux.

This EMF causes the current to flow when the conductor is closed. The magnetic field and conductor are two essential parts of the generator. The generator consists of a rectangular rotating coil that is rotating in a magnetic field around its axis.

The magnetic fields are provided by either permanents magnets or electromagnets. The ends of the coil are connected by two slip rings. The slip ring collects the induced current in the coil and transfers it to the external load resistance R. The rotating coil is called an armature, which is made of copper.

Also, Read: Types of Measuring Instruments

Key Differences Between Alternator and Generator:

  • Alternators are machines that convert mechanical energy from a prime mover to AC, while a generator converts mechanical energy from primer movers to AC or DC.
  • Alternator induces AC, whereas generator causes both AC and DC power. The generators generate an alternating current which is converted into DC with the help of a commutator.
  • The alternator has a rotating magnetic field, while the generator has a rotating magnetic field for high voltage output, and a low voltage static magnetic field is used.
  • The alternator takes the input supply from the stator while the generator takes the input supply from the rotor.
  • The armature of an alternative is stationary, and in the case of a generator, it is rotating.
  • The output emf of the alternator is variable, & the output voltage of the generators is constant.
  • Alternators have a wide range of RPM, while the generator has a narrow range of RPM (rotations per minute).
  • The alternator does not charge the dead battery completely while the generators charge the dead battery.
  • The outputs of the alternators are higher than that of the generators.

Also, Read: Keyless Remote Battery Is Low | When Does Key Fob Battery Replacing Replacing? | How to Replace a Keyless Remote Battery

Frequently Asked Questions (FAQ)

Generator Vs Alternator

An alternator is a device that converts mechanical energy into AC electrical energy. A generator is a mechanical device that converts mechanical energy to either AC or DC electrical energy. An alternator always induces an alternating current. A generator can generate either alternating or direct current.

What Is Alternator?

An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current.

Difference Between Alternator and Generator

An alternator is a machine that converts the mechanical energy from a prime mover into an AC, whereas the generator converts the mechanical energy from the prime mover into an AC or DC.

What Is Generator?

In electricity generation, a generator is a device that converts motive power (mechanical energy) into electric power for use in an external circuit.

How Does a Whole House Generator Work?

Whole house generators are wired directly into your home’s electrical system and connect directly to the fuel source. If the power goes out, these generators will turn on automatically. This means no trudging outside in terrible weather for the homeowner to restore power to their home.

Generac How Does It Work?

How It Works. A Generac home backup generator senses a power outage, turns on automatically, and delivers backup power to your home. It will run until utility power returns – whether that’s two hours or two weeks.

How Do Generators Work?

Electric generators work on the principle of electromagnetic induction. A conductor coil (a copper coil tightly wound onto a metal core) is rotated rapidly between the poles of a horseshoe-type magnet. The conductor coil along with its core is known as an armature.

How Does Alternator Work?

The alternator works by turning mechanical energy into electrical energy. When your engine is on, it powers a drive belt that rests on a pulley attached to the alternator. The pulley turns the alternator’s rotor shaft, which spins a set of magnets around a coil.

Leave a Comment

/* */