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:
Feb. 17, 2004
Filed:
May. 28, 2002
Jason T. Stauth, Concord, NH (US);
P. Karl Scheller, Bow, NH (US);
Glenn A. Forrest, Nottingham, NH (US);
Ravi Vig, Bow, NH (US);
Jay M. Towne, Newbury, NH (US);
Allegro Microsystems, Inc., Worcester, MA (US);
Abstract
A proximity detector includes an offset circuit for bringing at least one of a magnetic field signal and a tracking signal towards the other one of the magnetic field signal and the tracking signal when the detector output signal changes state. A magnetic field-to-voltage transducer provides the magnetic field signal indicative of an ambient magnetic field and a peak detector responsive to the magnetic field signal provides the tracking signal which substantially follows the magnetic field signal. A comparator generates the detector output signal which changes state when the magnetic field signal varies from the tracking signal by a predetermined amount.