Abstract: In an automobile electrical system having an alternator drivingly connected to a vehicle engine the alternator has a polyphase output winding producing a polyphase output in the form of a polyphase alternator voltage for each phase. A load dump apparatus and method for varying the output of the alternator employs a bridge coupled to the polyphase output winding and having a pair of direct voltage output terminals. The bridge has lower and upper switchable elements for each corresponding phase winding, the switchable elements are forward biased and connected in series across the output of the bridge and have a common or neutral input note connected to the corresponding phase winding. Each switchable element is controllable in accordance with a respective conduction signal applied thereto.

Abstract: A multi-voltage electrical system for a vehicle is described, which includes a generator and a voltage regulator; the voltage regulator regulates the output voltage of the generator to predeterminable values by varying the exciter current. Connected downstream of the generator are two rectifier arrangements, which lead to a terminal (B1) and a terminal (B2), respectively. At least the rectifier arrangement leading to the terminal having the lower voltage is designed as a controllable rectifier and is triggered by the voltage regulator in such a way that the desired voltage (UB1+) occurs. The other rectifier arrangement leads to the terminal (B2+), at which a higher voltage occurs, by suitable regulation of the exciter current. The controllable rectifier arrangement preferably includes six MOS field effect transistors.

Abstract: An energy supply device for an electromagnetic valve control of an internal combustion engine, in particular of a motor vehicle. The supply device has a generator which can be mechanically coupled to the internal combustion engine. A rectifier circuit which is assigned to the generator, has a first diode arrangement, as an anode part, and a second diode arrangement, as a cathode part, and to which a supply output is connected, and an electrical energy store. The electrical energy store is connected to the output of the third diode arrangement, and the energy supply device has a controllable DC/DC converter, which is connected on the one hand to the third diode arrangement and on the other hand to the supply output. As an alternative to the third diode arrangement, the DC/DC converter may be coupled in parallel with a voltage regulator and a diode to the first diode arrangement.

Abstract: A leakage current detecting coil is provided in the output circuit of the armature of a generator. The output of the leakage current detecting coil is connected to a gate control circuit for a pair of thyristors constituting a full-wave rectifier circuit provided between the output of the generator and the field coil thereof. The full-wave rectifier circuit controls the exciting current of the generator and also interrupts the exciting current through turning-off the thyristors when the leakage current is detected.