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:
Aug. 08, 1989
Filed:
Dec. 29, 1987
Richard P Strosser, Akron, PA (US);
Carl E Bohman, New Holland, PA (US);
Ford New Holland, Inc., New Holland, PA (US);
Abstract
A method and apparatus for cancelling cyclically recurring noise induced in a magnetic metal detector by movement of ferrous machine parts in the field of the detector provides for periodically sampling the output of the metal detector, delaying each sample for the duration of one cycle of the cyclically recurring noise, and subtracting the samples taken in one cycle from the output of the metal detector during the following cycle. The delay is accomplished by a delay line or shift register, or by storing the samples under microprocessor control. If the noise has a first component occuring at a first rate and a second component occuring at a second rate cancellation of both components may be accomplished.