A magnetoresistive displacement sensor for use with a number of different diameter magnetic recording media wheels carrying plural pieces of magnetic information recorded on at least on circumferentially running track, each of said different wheels having its associated magnetic information spaced with a predetermined constant wavelength (.lambda.), said sensor being disposed adjacently opposite to said magnetic recording media, said sensor arrangement comprising:
- at least two groups of magnetoresistive (MR) elements wherein each group includes a first plurality of elongated stripe-shaped MR elements in side-by-side relation with one another on the surface of a non-magnetic substrate, each of said MR elements extending in a longitudinal direction transverse to the direction of relative movement between the sensor and the magnetic recording media, the widths of said MR elements in the rotation direction being made substantially smaller than the wavelength (.lambda.) and each of said MR elements having a first and a second end;
- each of said groups comprising at least three MR elements, said first ends of said MR elements associated with each respective group being connected together, a first MR element in said first group being spaced a first predetermined distance from a second MR element in said first group in the direction of movement, said second MR element in said first group being spaced a second predetermined distance from a third MR element in said first group in the direction of movement, a first MR element in said second group being spaced a third predetermined distance from a second MR element in said second group in the direction of movement, said second MR element in said second group being spaced a fourth predetermined distance from a third MR element in the direction of movement, said third MR element of said first group being spaced a fifth predetermined distance from said first MR element of said second group, said second, third and fifth distances being substantially equal to one another and said first and fourth distances being substantially equal to one another and different from said second, third and fifth distances;
- means forming an output connection terminal at each respective second end of said MR elements, said output terminals extending in a longitudinal direction in a side-by-side manner along one side of said non-magnetic substrate;
- said connected first ends of said MR elements associated with said first group forming means for a first external power supply connection terminal and said connected first ends of said MR elements associated with said second group forming means for a second external power supply connection terminal;
- said first and second external power supply connection terminals extending to a position adjacent said output connection terminals provided at said second ends of said MR elements;
- said second end of one of said three MR elements in said first group being arranged for selective external connection to said second end of one of said three MR elements in said second group so that the distance between said selectively connected MR element in said first groups and said selectively connected MR element in said second group is substantially equal to an odd multiple of .lambda./2, said second end of another one of said three MR elements in said first group being arranged for selective external connection to said second end of another one of said three MR elements in said second group so that the distance between said selectively connected another MR element in said first group and said selectively connected another MR element in said second group is substantially equal to an odd multiple of .lambda./2;
- said selectively connected one MR element in said first group being spaced a distance equal to an odd multiple of .lambda./4 from being selectively connected another MR element in said first group and from said selectively connected another MR element in said second group, and
- said selectively externally connected second end of said one MR element in said first group and said selectively connected MR element in said second group respectively forming a first output connection, and said selective externally connected second end of said another MR element in said first group and selectively connected second end of said another MR element in said second group, respectively, forming a second output connection.