Abstract: A high efficiency automotive electrical system and method of control employing an asynchronous induction machine for performing both starting and generating functions. The induction machine is coupled to the engine through a bimodal gearset which operates as a reduction drive during the starting mode and as a direct drive during the generating mode. A computer-based controller responsive to the battery voltage and the speed of the induction machine maintains given voltage/frequency ratios during both starting and generating to provide efficient operation, and smoothly controls the transition between starting and generating modes. The vehicle electrical loads are supplied at one or more stable voltages produced by a load converter powered by the battery.

Abstract: A dual voltage motor vehicle electrical system. First and second batteries are series connected across the output terminals of a battery charging generator. A converter is provided that can charge the first battery from the second battery or charge the second battery from the first battery. The voltages across the batteries are sensed and the battery with the lower voltage is charged from the other battery. The system has current limit and temperature limit controls for protecting semiconductor switches that are utilized in the system.

Abstract: A separable series of secondary cells is connected across a charge circuit upon the application of supply potential. When the charge potential level upon a selected portion of the secondary cell series attains a predetermined magnitude, the selected portion is disconnected from the charge circuit. When the charge potential level upon the remainder of the secondary cell series subsequently attains a predetermined magnitude, all of the secondary cells are reconnected in series until the charge potential level upon all of the secondary cells of the series attains another higher predetermined potential level at which time the charge circuit is disabled.