Patent ID: 7388368

Claim:
An encoder for a position sensor, of the type including a multipolar magnetic ring ( 2 ) provided, on its circumference, with alternately positioned poles having polarities of opposite signs and intended to move past a measuring cell ( 3 ) delivering a periodic signal corresponding to the change in the intensity of the radial component of the magnetic induction delivered by the poles, the encoder including at least one junction (J) between one so-called small pole (P) and one so-called large pole (G), having an angular width larger than the angular width of the small pole, the small pole (P) and the large pole (G) corresponding to each junction (J) having polarities of opposite signs, characterized in that, for each junction (J), the large pole (G) of a given sign consists: of at least one small stabilizing pole (ps) of the same sign placed adjacent to the small pole (P) of opposite sign and having an angular width substantially identical to that of said small pole on the one hand, and of at least one complementary pole (pc) of the same sign as the stabilizing pole (ps), the complementary pole (pc) and/or the small stabilizing pole (ps) having a gradual magnetization profile adapted for stabilizing the passing through zero gauss of the radial component of the magnetic induction, on the other hand.