The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1998
Filed:
Jun. 04, 1996
Arthur L Dean, Indiana, PA (US);
Michael Steven Giusto, Cupertino, CA (US);
FMC Corporation, Chicago, IL (US);
Abstract
This invention pertains to sensorless measurement of electromagnetically induced displacement in actuators and similar units. Primarily, the device imposes a constant frequency and amplitude excitation sine wave on a coil through a fixed impedance of a drive isolation network. The amplitude and phase of the voltage across the coil fluctuate depending upon the coil's inductance. This variation in the value of the inductance is dependent upon the change in magnetic flux density generated by the coil current and the displacement in air gap between the coil pole and armature. Accordingly, a measurable magnitude of displacement can be controllably imposed upon a system of solenoids. The displacement is thus measured and set without the use of extrinsic sensors.