Alternators vs. Generators: What Are Their Differences?

When you are looking to power your vehicles, engines, and motors, you may choose to employ either an alternator or a generator. Both options are reliable choices for producing electrical current, and both operate on Faraday’s Law of Electromagnetic Induction. Simply put, this law states that “the magnitude of voltage is directly proportional to the rate of change of flux.” In other words, there must be relative motion between a magnetic field and a conductor to induce voltage in a system. The main difference between alternators and generators is how they achieve this relative motion. In generators, an armature rotates to create this motion, while in alternators, the armature may move or remain stationary. To better understand how these differences affect the functions of each, this blog will explore the key differences between alternators and generators.

While both alternators and generators rely on mechanical energy to generate electrical energy, they each produce different currents. Alternators strictly generate alternating current (AC) while generators function to produce power in the form of both alternating current and direct current (DC). With a rotating magnetic field, an alternator may alternate between two currents of equal magnitudes and of opposing polarity without a moving armature. To achieve this, an alternator relies on magnetic flux to cut the stator conductor. This induces an electromagnetic field and current in the armature conductor which first rotates in a clockwise direction and then in a counterclockwise direction, generating the alternating current.

Meanwhile, in a generator, both stationary and rotating magnetic fields are used, the former for DC and the latter for AC. Producing both AC and DC, generators work in two different ways.  For a generator to achieve DC, the rotor is placed inside the stationary magnetic field, that of which is produced by the magnetic poles. The rotor moves inside the magnetic field, intersecting the magnetic line of force in order to induce current in a wire. To create AC, or to switch the direction of the current, a generator’s rotor will complete a half rotation, cutting the magnetic flux. For this to work, the ends of the circuit must be connected directly to the load. On the other hand, to produce DC energy, the ends of the wire are connected to a commutator, that of which does the work of converting AC to DC.

While an alternator is smaller in size and requires less space than a generator, it produces a higher output EMF; however, the output of an alternator is variable and the output of a generator is constant. Alternators also boast the advantage of offering a proficient charge at idle speeds. Regardless of which option you choose, it is important to have a reliable power source for all of your operations, so be sure to source all of your power and aircraft parts from a reputable distributor like Aviation Store Online.

Owned and operated by ASAP Semiconductor, Aviation Store Online is a leading online distributor of high-caliber aircraft components from manufacturers across the globe. Offering access to an unparalleled inventory of over 2 billion new, used, obsolete, and hard-to-find parts, we invite you to explore our listings at your leisure before submitting a Request for Quote (RFQ) form for any items that pique your interest. To receive a customized quote within 15 minutes or less, be sure to include all relevant details in your submitted forms. Our team of experts uses information like target prices, shipping deadlines, and desired quantities to formulate quotes that meet your unique needs. To learn more, contact us at any time via phone or email!


October 12, 2022

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