Vehicular power supply system having a plurality of power supply voltages

• Main Authors: MASHINO; KEIICHI, MASUMOTO; SOUJU
• Format: Patent
• Language: English
• Published: 29.11.1988
• Edition: 4
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

A vehicular power supply system having a plurality of power supply voltages comprises a generator including first and second armature windings electrically isolated from each other and a field winding, a first rectifier unit converting a first a.c. output of the first armature windings into a first d.c. voltage, a second rectifier unit converting a second a.c. output of the second armature windings into a second d.c. voltage, a first battery connected to an output terminal of the first rectifier unit, a second battery connected in series with the first battery and connected also to an output terminal of the second rectifier unit, a first voltage regulator detecting the terminal voltage of the first battery thereby controlling current supplied to the field winding of the generator, a second voltage regulator detecting a mean voltage of the second battery thereby controlling on-off of a power switching element connected between the second battery and the second rectifier unit, the second voltage regulator acting to decrease the conduction ratio of the power switching element when the mean voltage of the second battery is high but to increase the conduction ratio when the mean voltage is low.