Eldec Corporation

Crane Company

Kevin G Woolsey

Jeff Lamping

Steve Knudson

Bernie Burreson

John Marler

Bernard J Burreson

Alan Orr

L Mark Marion

Patrick A Knappert

Steven Knudson

A Hall effect generator chip is mounted between adjacent ends of an annular, horseshoe spacer of nonmagnetic material. The generator is sensitive to the flux density (B field) tangential to its top and bottom surfaces. The spacer and generator are sandwiched between ferromagnetic rings, each having a small air gap overlying/underlying the generator. A circuit including the generator supplies an output linearly proportional to the current of an adjacent conductor with reduced hysteresis and small variability over a temperature range.

Current sensor

A target device is carried by or mounted on a first part movable relative to a second part. The second part has a sensing device including an array of sensors providing outputs responsive to the magnet field of the target device. A processing device receives the outputs of the sensors and calculates relative positions of the two parts based on the outputs.

Position indicating system

A core of a proximity sensor is made of a highly permeable metal and is shaped and sized to operate as a saturable core proximity sensor, a variable reluctance proximity sensor, and an eddy current proximity sensor. The core has a cross-sectional shape including a head portion, two legs extending from the head portion, and two foot portions (feet) extending from the two legs. The head portion forms a substantially planar section along the upper surface and is perpendicular to the sectional direction created by the two legs. The sectional direction of the two legs are perpendicular to the sectional direction of the two feet. The two feet are in a common plane along the bottom surface. Both foot portions are also parallel to the head portion. The cross-sectional shape of the core may further comprises two tail portions (tails), wherein each tail extends from one of the two foot portions in a direction toward the upper surface.

Inductive proximity sensor for detecting ferromagnetic, non-permeable or magnet targets

An omega-shaped core is wrapped with two coils arranged to be responsive to magnetic permeable metal and conductive metal objects. The omega core allows the proximity sensor to operate as a saturated core sensor, a variable reluctance sensor or an eddy current loss sensor. The core is made from a thin, highly permeable metal that is preferably formed from a single piece of sheet metal, and comprises a substantially flat, rectangular member bent in four locations to form a head portion, two legs, and two feet. The bends form right angles so that the head portion is perpendicular to the two legs, and the two legs are perpendicular to the two feet. The two feet are parallel to each other and also parallel to the head portion. The core is positioned in a housing with two inductive coils, each coil being positioned around a leg portion of the core. A calibration bolt can be placed through the center of the core to change the level of inductance measured from the two inductive coils.

Disclosed is a method of designing a position sensor having a plurality of coils so that the total impedance of the sensor varies according to a desired impedance function. The method includes the steps of modelling the position sensor on a computer using a finite element analysis program to determine the vector potential and current density within the sensor due to a known current flowing in each of the coils. A set of matrix equations is then developed that relates vector potential, the current density and the number of turns, N.sub.i, in each coil to a point on the desired impedance function. The set of matrix equations is then optimized to determine the number of turns, N.sub.i, that each coil should contain, so that the total impedance of the sensor varies according to the desired impedance function.

Growing community of inventors

Snohomish, WA, United States of America

Kevin G Woolsey