Patent ID: 8638073
Filing Date: 2014-01-28
Classification: H02P

Abstract:
1. A control device for a vehicle AC generator, in which a DC voltage, obtained by rectifying an AC output voltage of an armature coil in said AC generator that has said armature coil and a field coil with a rectifier, is applied to said field coil to obtain a field current, and the field current is controlled by ON/OFF control of a switching element connected in series to said field coil, the control device for the vehicle AC generator comprising an upper limit restriction unit in which an upper limit of on-duty of said switching element is set to a ratio: set voltage/DC voltage, wherein the set voltage is a voltage capable of continuing energization when the field current of the field coil is on-duty 100%, and wherein a resulting value is converted by an upper and lower limit clip circuit generating the on-duty of said switching element.