alternátor

Alternátor is an electrical generator that converts mechanical energy into electrical energy in the form of alternating current. In most vehicles, the alternátor provides power to the electrical system and charges the battery while the engine runs. The alternating current produced is converted to direct current by a diode rectifier before entering the vehicle’s DC electrical system, and a voltage regulator maintains a stable output.

The main components of an alternátor are the stator (a stationary winding set), the rotor or rotating field (an electromagnet), a diode bridge (rectifier), and a voltage regulator. The rotor’s magnetic field, excited by a small DC current through brushes and slip rings, rotates within the stator windings to induce AC voltage. The rectifier converts this to DC, suitable for the battery and electrical loads, while the regulator adjusts the field current to control the output and prevent overcharging.

In automotive use, alternátors are typically three-phase devices and are preferred over older dynamos because they deliver substantial output at low engine speeds, operate without the heavy commutator, and require less maintenance. They are designed to withstand automotive temperature variations and varying electrical loads.

Beyond vehicles, alternátors are used in various applications where compact, reliable AC generation is needed, or where AC must be converted to DC for charging batteries. Large-scale power generation relies on similar alternating-current generators, often called synchronous generators, integrated into grid systems.

Common maintenance considerations include checking drive belt tension, battery condition, and the integrity of the rectifier and regulator. Failures may present as dim lights, battery warning indicators, unusual noises, or unexplained battery discharge.