Patent ID: 6867569

Claim:
An abnormality detection apparatus of a vehicle AC generator including a multiple phase armature winding and a rectifier having a plurality of rectifying elements that is connected to the armature winding to provide ripple-including outout voltage, said abnormality detection apparatus comnrising: abnormality judging means for judging abnormality of said vehicle AC generator, said abnormality judging means including ripple detecting means for detecting the number of ripples for a predetermined period to judge an abnormality if the number of ripples that is detected is less than a predetermined number and alarming means, connected to said abnormality judging means, for displaying an alarm when said abnormality detecting means judges said abnormality, wherein said abnormality judging means judges abnormality if the number of ripples that is detected is less than a number defined by an expression km−j for said predetermined period; where m is the number of phases of said multiple phase armature winding, j is the number of said rectifying elements and k is an integer that is 1 or larger than 1.