CHARGING GENERATOR AND VOLTAGE REGULATOR

摘要

PROBLEM TO BE SOLVED: To avoid generation of overvoltage due to failure of machine by suppressing the field current flowing through a field winding and regulating the DC voltage to a protective interruption voltage through a voltage regulator thereby setting a breakdown voltage higher than the protective interruption voltage. SOLUTION: When a generated voltage on the low voltage side detected at terminal S exceeds a predetermined level, a Zener diode 138 breaks down to conduct a transistor 134. Consequently, a power transistor 131 is interrupted and a field current flowing through a field winding 10d is inputted to terminal F of a voltage regulator 13 and attenuated through a flywheel diode 132 and thereby the field current is suppressed. Subsequently, the charging voltage outputted from terminal B of a charging generator 1 lowers and a voltage on the low voltage side being detected at terminal S drops below a predetermined level. The Zener diode 138 thereby breaks up to interrupt the transistor 134 and the field current flowing through the field winding 10d increases to regulate the voltage on the low voltage side at a constant level.