INDUCTIVE POSITION DETECTION DEVICE

摘要

A coil section includes a primary coil which is magnetically excitable by an AC signal, and secondary coils which are provided so as to generate an inductive output in response to excitation of the primary coil. A self-oscillation circuit, including an inductance element and a capacitor, has incorporated therein the primary coil as the inductance element for self-oscillation. A target section is provided in such a manner that its relative position to the coil section varies according to a position of a target of detection, and the target section includes a magnetically responsive member disposed so that inductance of the secondary coils is varied according to the relative position. Amplitude levels of the output signals of the secondary coils are extracted, and position data of the position of the target of detection is obtained on the basis of these amplitude levels.

主权项

1. An inductive type position detection device comprising:
a coil section including a primary coil excitable by an AC signal and a secondary coil disposed to produce an induced output in response to excitation of the primary coil; a self-oscillation circuit composed of the primary coil included in said coil section and a capacitor, said self-oscillation circuit having incorporated therein the primary coil as an inductance element for self-oscillation; a target section disposed in such a manner that a position of the target section relative to said coil section varies in response to a position of a target of detection, said target section being formed of a magnetically responsive member constructed to vary inductance of the secondary coil in said coil section in response to the position of the target section relative to said coil section; and output circuitry for outputting position data of the target of detection based on an amplitude level of an output signal of the secondary coil.