Method & apparatus for managing alternator loads on engines

Abstract

The improved engine load management system of the present invention includes an apparatus that will de-excite the field coils of an alternator that is driven by an internal combustion engine when the battery that the alternator charges is above a required minimum voltage and when the engine is operating under high load conditions such as acceleration or climbing. When the battery charge falls below the required minimum, the apparatus excites the alternator field coils and permits the alternator to charge the battery despite a high engine load condition. When the battery charge is above the minimum required voltage, but below the voltage at which charging is discontinued, and the engine is under high load, the alternator field coils are energized and de-energized in a cycle that reduces alternator drag on the engine, but permits limited battery charging to occur. The limited charging rate is greater as the battery voltage is lower, and the change from lesser battery charging to greater battery charging is linear and inversely related to the charge of the battery. When the engine is operating at normal load conditions, such as cruise, battery charging is accomplished on demand under normal circumstances. Deferring battery charging by limiting alternator field coil excitation, reducing alternator drag on the engine during heavy load conditions (an inherently inefficient operating regime for internal combustion engines) increases fuel economy and decreases atmospheric pollutants from automobiles equipped with the apparatus of the current invention.