Battery charging apparatus with fault detection

摘要

The battery charging apparatus includes a generator, main voltage regulator, an auxiliary voltage regulator, at least one consuming device and a protective circuit having circuit portions for recognizing and signalling faults via a charge control lamp. The generator output voltage is rectified with rectifier bridges containing Zener diodes. Voltage comparison to threshold values and logic circuitry for processing the comparison results are used to determine the presence of faults in the operation of the battery charging apparatus. The fault detection device detects conduction defects in the main voltage regulator and/or interruption in the generator excitation circuit. The logic circuitry determines whether simultaneously both a supplied voltage exceeds a threshold value and the main voltage regulator is turned on longer than a predetermined time interval to indicate its continuous operation. After a fault is detected voltage regulation is performed by the auxiliary voltage regulator until the fault is eliminated so that the rectifier bridges are not destroyed. The battery charging apparatus described is particularly suitable for use in motor vehicles.