The voltage supply device for the motor vehicle electrical system includes e.g. a self- or separately-excited generator having stator windings (10,11,12) and an excitation coil (E); a main bridge rectifier device connected to the stator windings having a first connector (B+) at which a first voltage (UB+) is delivered; an exciter bridge rectifier device connected to the stator windings; an exciter voltage regulator device connected between the exciter bridge rectifier device and the excitation coil (E) for regulation of an excitation current passing through the excitation coil; an additional rectifier device connected to the stator windings (10,11,12) having a second connector (B2+) at which a second voltage (UB2+) is tapped and a device for regulating a load current delivered by the generator to the first connector (B+) or the second connector (B2+) that includes a thyristor (Th0,Th4) connected to the first or second connector and a triggering device (A) whereby the generator has an optimal power output. During full load operation the load current is limited with the load current regulating device, while during partial load operation the exciter current is regulated by the exciter voltage regulator device. The invention can also be applied to voltage supply systems with permanently excited generators.
The invention relates to an electrical power supply system for an automobile vehicle comprising an alternator, a first battery with a voltage less than the electromotive force of the alternator, and a second battery with a higher voltage. The first battery is charged while the inductance internal to the alternator is being charged and the second battery is charged while this internal inductance is being discharged. This system comprises for each alternator phase, a controlled switch in series with the first battery, and a diode to charge the second battery, and control means for each controlled switch such that the first battery is charged when this controlled switch is closed, and when the controlled switch is opened after the inductance has been charged, the inductance discharges into the second battery.
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.
A method of operating an alternator of a motor vehicle includes the steps of monitoring an amount of stored electrical energy available to operate the vehicle, estimating a vehicle electrical load, and regulating an output of the alternator based at least in part on the amount of electrical energy available to the vehicle and the estimated vehicle electrical load.
An alternator for a motor vehicle includes a current generation device and a rectifier. The current generation device has multiple phase stator windings in which AC currents are generated. The rectifier is connected to the windings of the current generation device. The rectifier includes multiple sets of first and second diodes for the multiple phase windings. At least one of the first and second diodes of each set is a Schottky diode. A voltage clamping device is connected to the rectifier to protect the Schottky diodes from surge reverse voltage.
