What is the difference between a generator and alternator?
Alternators and generators both convert mechanical energy to electrical energy. Despite this similarity, these electrical generators have a number of differences in not only the way they generate electrical current, but also in their respective efficiency and usages.
This general guide on the differences between generators and alternators should hopefully address some questions you might have regarding these two types of electrical energy components.
Generating current
In an alternator a magnetic field rotates around a stationary armature. For an alternator to generate energy, an engine turns a pulley which is attached to the alternator. This then rotates the rotor shaft which creates a magnetic field that generates alternating current (AC) around the coil of the rotor shaft. This current is supplied to the output load through brushes. Due to the revolving magnetic field, the current supplied is always AC, as the magnetic polarity is continuously being flipped.
A generator, on the other hand, utilises an alternating armature inside a stationary magnetic field- the opposite of how an alternator operates- and generates AC or direct current (DC). The type of current depends on whether a slip ring or a commutator component is used. If a slip ring is used, then the generator will produce AC, whereas a commutator facilitates DC.
Efficiency
Since alternators and generators work very differently, their respective resource efficiency is unsurprisingly varied too.
Alternators actually conserve energy, as energy can be supplied as and when needed by varying the load. This also means that batteries maintain a longer life, due to the avoidance of overcharging. In addition to better energy conservation, alternators also have an increase mechanical life as the brushes which carry the AC to the output are not worn by friction, owing to the static properties of the armature.
On the other hand, generators do not boast the higher efficiency levels of alternators. Generators maintain a constant output voltage and are less efficient because of this.
Uses
We have established that the efficiency of alternators and generators is varied, and this directly factors into the suitable uses of both types of convertor.
You will find alternators being used in heavy machinery electrical systems, as they are responsible for keeping your battery fully charged and also power electrical components such as lighting, control, and management systems. Alternators cannot, however, be used to charge a completely drained battery.
The constant output voltage of generators and their typically larger size means that generators are actually ideal for supplying backup power, and can be used in mining and construction where power grid supply is unfeasible. Furthermore, unlike alternators, generators can be used to charge fully drained batteries.
Founded in 1995, Jaytrac has supplied high quality parts for our customers’ heavy machinery for 27 years. We stock a wide range of components for Caterpillar, Komatsu and Cummins machinery, including alternator parts. For any further questions or information on alternators and generators, or the parts we offer, please contact us today on 01604 491133 or email us at sales@jatrac.co.uk