Abstract: In a method for regulating the excitation current of an inductor of a motor vehicle alternator, the alternator is of the kind comprising a rectifier bridge supplying a rectified voltage (which is to be regulated) having a low frequency fluctuation of variable amplitude with a high frequency waveform of constant amplitude superimposed on it, the rectified voltage Ub+ being thus a periodic voltage, each cycle of which comprises a first alternate period, during the course of which a voltage is applied to the inductor of the alternator, and a second alternate period, during which no voltage is applied to the inductor.

Abstract: The invention relates to a high voltage electrical power supply device for an auxiliary circuit CA of a motor vehicle.The device comprises an alternator 1 having two identical stator windings 11 and 12, each connected to a rectifier bridge 13 and 14 supplying a rectified alternator voltage on a terminal B+1, B+2 an excitiation regulator 2 enabling the regulation of the excitation current of the inductor winding of the alternator and means for parallel-series/series-parallel switching of the stator windings. Alternator output terminals B+1, B+2 are provided for generating a nominal value voltage or a high voltage. A control logic is interconnected with the excitation regulator 2 and the switching means 3 to ensure the starting of the high voltage operation conditionally with respect to status parameters of the vehicle such as the engine speed, the clutch position, the temperature of the vehicle, and the supply voltage of the device.

Abstract: The invention relates to a device for supplying electricity at overvoltage in an automobile.Automobile circuits comprise a main circuit (1) and an auxiliary circuit (2) requiring to be temporarily supplied at overvoltage. The main circuit is normally supplied by a battery (3) fed by an alternator (4) of which the excitation circuit is regulated by a regulator (5). In accordance with the invention, the device includes commutation means (6) controlled from the stator output of the alternator on the auxiliary load (2), the excitation of the alternator (4) following this commutation being taken via the regulator (5) to a sufficient value as a function of the state of the engine (M) for assuring a temporary supply state of the auxiliary circuits (2) at overvoltages and at reduced current.Application to supply of electric circuits of automobiles or the like.