Patent ID: 7116032
Filing Date: 2006-10-03
Classification: H01R,H02K

Abstract:
1. An automotive alternator brush abrasion detection system comprising: an automotive alternator provided with: a case; a shaft rotatably supported in said case; a rotor fixed to said shaft and disposed inside said case for generating a rotating magnetic field, said rotor being provided with: a rotor coil in which a magnetic flux is generated on passage of an electric current; and a plurality of magnetic poles magnetized by said magnetic flux generated in said rotor coil; a stator mounted to said case so as to cover an outer circumferential side of said rotor, said stator being provided with a stator winding in which an electromotive force is generated by said rotating magnetic field generated by said rotor; a pair of electric current supplying members disposed so as to be separated in an axial direction on a first end portion of said shaft and be able to rotate together with said shaft, said pair of electric current supplying members being electrically connected in series by means of said rotor coil; a brush holding apparatus disposed inside said case so as to be positioned radially outside said pair of electric current supplying members; a rectifier disposed inside said case for rectifying and outputting said electromotive force from said stator winding; and a voltage regulator disposed inside said case for adjusting a magnitude of said electromotive force in said stator winding, wherein a resistance value of an electric current path in which a portion of said electric current flowing through said rotor coil is diverted to flow through said contact during contact between said elastic member and said contact is equal to or greater than five times a resistance value of said rotor coil.