Abstract: A position sensor includes a coil of small diameter litz wire wound around a ferrite rod. The rod is secured in the end of a ceramic support and an end cap is secured on the other end of the rod to form a bobbin section on which the coil is wound. Two palladium silver strips are formed axially along the length of the support extending from the bobbin section to near the base of the support. Two free ends of the coil are formed into strain relief loops and soldered to the strips. Lead wires of comparatively larger diameter are also soldered to the strips but near the base of the support. The strips establish electrical continuity between the coil and the lead wires while separating the end portions of the coil from the lead wires so as to prevent the lead wires from inducing stress into the relatively fragile coil wires.

Abstract: An Eddy current position sensor for providing an electrical signal proportional to the position of a metallic ring positioned around and movably positionable axially along the length of an elongated wire wound core. The metallic ring serves as a movable target with respect to the fixed coil/core and may be made buoyant for liquid level measurement or connected to other movable objects. The electrically conductive wire winding around the elongated preferably cylindrical ferromagnetic core has a progressively increasing spacing between each turn of wire from one end of the coil to the other. Each end of the wire is connected to a linear oscillator and signal conversion unit which serves to both input a radio frequency current through the coil and to monitor the absorption of the metallic ring around a conical shaped electromagnet field produced by the energized coil. The field absorption by the metallic ring varies linearly with the axial positioning of the ring over the coil.