Monotonically changing skew in a magnetostrictive anisotropic thin film plated wire line sensor

Claim 1

An improved plated wire for use in an intrusion detection system which uses as a transducer an extended length of strain responsive anisotropic thin film plated wire, the source end of the wire being energized by the output of a high frequency oscillator and in which system because of losses in the plated wire it is desired that the voltage vs. strain response of the wire at the remote end produces a larger electrical signal at that point than the same strain at the source end, the improved plated wire comprising: an extended length of wire substrate; and a strain responsive anisotropic magnetostrictive thin film deposit on said substrate, said deposit being monotonically varied along the length of said wire in that the magnetization skew angle is progressively increased thereby providing a controlled skew variation along the length of said wire so that the voltage vs. strain response along the length of said wire increases progressively from a relatively low level response at the source end of the wire to a relatively large response at the remote end of the wire.