Automotive alternators replaced generators in the 1960s due to their ability to charge car batteries and run electrical devices while the engine is idling. Unlike generators, alternators spin the magnet instead of the windings, resulting in stronger current and easier connection to the car’s electrical system.
Automotive alternators transform the mechanical or kinetic energy of an engine into electrical energy that is used to charge the battery and operate electrical devices in the car, such as the headlights, radio, and air conditioning system. Prior to the development of automotive alternators, automobiles relied on generators to accomplish this, but they had some significant drawbacks. Developed in the early 1960s to overcome the shortcomings of generators, automotive alternators were quickly adopted by automobile manufacturers as a lighter, more reliable replacement.
Generators and alternators work on the same principle: when a conductor passes through a magnetic field, an electric current is produced in the conductor. A generator consists of a complex arrangement of wires wound around a frame that is turned on a pulley by a belt connected to the motor. These ‘windings’ are made to rotate within a magnetic field created by powerful magnets placed in a fixed casing around the frame of the winding, creating an electric current in the wires. Current is passed to the battery and the rest of the electrical system via a commutator, a system of metal brushes attached to the windings that rub against the metal contacts as the windings rotate.
However, the output of an automotive generator is insufficient to charge the battery while the engine is idling. This is a serious drawback, especially in cold climates where cars need to be warmed up before they can be driven. Operators would sit in their cars and rev their engines to produce enough power to keep their batteries charged. This was a dilemma for most drivers: they had to decide whether to waste gas to rev the engine or let the engine idle and risk the battery dying before the engine warmed up properly. It was this significant disadvantage that the alternators were designed to overcome.
The biggest difference between generators and alternators is what is rotated. Where generators spin the windings, automotive alternators spin the magnet; the windings are contained in the casing within which the magnet or rotor rotates. Although the windings are fixed, the magnetic field moves around them and electric current is created just like with the generator. The first advantage of this construction is that the connection to the car’s electrical system is much easier, with no moving parts to wear out. From the perspective of manufacturers and operators, the most important advantage is that automotive alternators produce much stronger current and can charge a car battery and run the various electrical components of modern vehicles, all while the engine is idling.
Protect your devices with Threat Protection by NordVPN
