Control apparatus for onboard AC generator for motor vehicle

摘要

A control apparatus for an onboard AC generator for a motor vehicle is capable of suppressing erroneous operation of the switching circuit due to a leakage current to thereby prevent the output voltage of the AC generator from abnormal rising. The control apparatus includes an AC generator (1) including a field winding (102), a rectifier circuit (2) for converting an output voltage of the AC generator (1) into a DC voltage, a battery (5) charged with the DC voltage, a switching circuit (3) constituted by a low-side switch for turning on/off a current flow loop extending through the field winding (102), a control unit (4) for controlling on/off-operation of the switching circuit (3) so that a voltage (VB) appearing at a charging terminal of the battery (5) matches with a predetermined voltage level, and a resistor (303) inserted between a control input terminal of the switching circuit (3) and the ground potential.