Is an AC Generator an Alternator?

When it comes to products, labels are important because they convey what the product actually is to the end-user. Labels can be confusing, however, when they incorporate terms the usual consumer might not understand, so being as clear as possible is also important if you want to sell your product in a fair and safe way. In the case of AC generators, you can usually assume that an alternator is a kind of AC generator, but there are a few nuances that are implied if something is called an alternator.

Firstly, you can expect an alternator to output alternating current, and this is a fairly important distinction to make when it comes to power supplies. If you need to provide an AC voltage to a device and you supply a DC (or "direct current") voltage instead then you can expect to encounter several problems—one of which is likely to be the destruction of the device in question. Examples of sources of direct current voltage include batteries and solar cells. If you have a DC voltage source but need to use it with a device that requires an AC voltage input, you should consider adding an inverter to make sure everything works properly.

What is an alternator?

The word "alternator" is heard most commonly in reference to internal combustion engines like those in cars. This is because the main function of an alternator is to convert the mechanical energy of something to electrical energy with an AC current, and while cars don't necessarily need electrical energy to propel themselves forward, they certainly need it to get conveniences like the air conditioner or even the approximately 100 million lines of code that operate inside a more modern vehicle. 

Put simply, the way an alternator generates electricity is by rotating an electromagnetic field quickly inside a set of stationary copper wires. When the magnets are put into motion in this manner by a mechanical force, it generates electricity through electromagnetism. In the case of cars, this electricity is actually routed through a diode to convert its current to DC because that is the kind of current used to power the car's systems and recharge the battery as needed.

Direct Current vs. Alternating Current

AC generators convert mechanical power into electrical power with alternating current by definition, and since we established that alternators do exactly this, we can be certain that if something claims to be an alternator, it is also an alternating current generator. Likewise, you can generally expect something that is called a generator to produce power with a DC current, if that generator's label does not otherwise specify what kind of current it provides.

While direct current is not without its merits, alternating current is far more prevalent. Not only do DC generators tend to be less reliable than AC alternators, the resultant AC voltages are compatible with transformers as well. Transformers allow for the increasing and decreasing of the AC voltage. This is very useful for the long-range transmission of power over power lines without voltage loss, and this is something that DC voltage has historically struggled to do. 

In summary, an alternator is, in fact, the same thing as an AC generator. An AC alternator is a common device that you can find anywhere, from your car to the local power plant. So if you are looking to generate power for a standardized device, you will probably need to utilize one. That being said, you need to be certain that you aren't using the wrong kind of power with your devices, so don't be afraid to invest in an inverter if you think it will be a problem.