Abstract: In a device and a method for regulating an alternator increased alternator output is achieved either in that the exciter current can have a value above the nominal exciter current or in that the alternator control parameters are fixed in such a way that overheating could occur under unfavorable circumstances. In order to prevent this overheating even under unfavorable circumstances, the temperature is measured preferably in the regulator and the temperature at critical locations is determined from this temperature while taking into account typical parameters. This can be effected in that the temperature or temperatures which would occur in stationary operation are first determined. When an impermissible temperature is detected, the exciter current is reduced by suitable steps until the allowable maximum temperature is not exceeded.

Abstract: The battery charging system includes a generator, a rectifier system with main diodes and exciter diodes as well as two terminals (B+, D-) for battery charging, at least one terminal (D+) for consuming points, a voltage regulator (14) for a generator output voltage, a charging control light (16) and a fail-safe device (15) structured to indicate faults and for protection from excess voltages. The fail-safe device includes an additional voltage regulating device (17) connected electrically to the generator and a relay (27) connected with the additional voltage regulating device.

Abstract: To protect the battery in an automotive electrical system against over-charging upon failure of the voltage regulator to control current flow through the field of an automotive alternator, the field current is conducted through an interruptable network element, for example a fuse or a relay controlled switch. A voltage sensing network, for example a Zener diode, is connected to control current flow through a controlling element, for example a thyristor, which provides either an auxiliary current to burn out the fuse or a control current to the relay coil to interrupt connection to the field if over-voltage has been sensed. Simultaneously, an indicator lamp can be energized to indicate malfunction of the voltage regulator.