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:
Apr. 08, 1986
Filed:
Feb. 21, 1984
David P Erdmann, Hopkins, MN (US);
Dennis L Kurschner, Minnetonka, MN (US);
John C Timmerman, St. Paul, MN (US);
Honeywell, Inc., Minneapolis, MN (US);
Abstract
In combination: an air core coil; a passive detector connected to said coil for giving a first output in response to change in the ambient magnetic field due to movement of a magnetic body near the coil; an active detector connected to the same coil and operable to create a local magnetic field about the coil and to give a second output in response to changes in the local field due to the movement of the body; apparatus energizing the active detector in response to the output of the passive detector; and apparatus giving a further output in response to simultaneous outputs from both the detectors.