Patent ID: 7358640

Claim:
An automotive rotary electric machine comprising: a rotor having: a field winding for generating a magnetic flux on application of an excitation current; a plurality of magnetic poles magnetized by said magnetic flux; and a current receiving portion electrically connected to said field winding; a power supply mechanism portion having: a brush in contact with said current receiving portion; a brush abrasion limit sensing portion for sensing that said brush has abraded to a predetermined length; a brush abrasion limit detecting means constructed so as to monitor an output from said brush abrasion limit sensing portion, to enter a brush abrasion limit detection state at a point in time when said output exceeds a set value, and including switching means for thereafter maintaining said brush abrasion limit detection state regardless of whether said output exceeds said set value; a stator having a stator winding in which an electromotive force is generated on application of a rotating magnetic field accompanying rotation of said rotor; and a controlling means for controlling an output voltage from said stator so as to be constant, wherein said brush abrasion limit detecting means and said controlling means are constructed in a single integrated circuit.