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. 05, 1991
Filed:
Nov. 29, 1988
Homer E Henschen, Carlisle, PA (US);
Michael J McKee, New Cumberland, PA (US);
Joseph M Pawlikowski, Lancaster, PA (US);
AMP Incorporated, Harrisburg, PA (US);
Abstract
A self-redulanting heater includes an electrically-conductive substrate (11), having a magnetic surface layer (13) of one skin depth, folded 180 degrees to define two heater sections joined by a fold section. The magnetic material has a considerably higher resistance than the substrate material. The surfaces of the two sections clad with the surface layer are in closely spaced parallel relation and connected in series by the fold section (23) such that a constant amplitude alternating energizing current flows in opposite directions through the two sections at any instant of time to thereby establish an electric field between the two heaters. The field concentrates current flow at the two facing surfaces. Depth of the current is determined by the skin effect phenomenon and increases significantly at temperatures above the Curie temperature of the magnetic material.