Patent ID: 6392528
Filing Date: 2002-05-21
Classification: H01C,H02H

Abstract:
A generally rectangular electrical overcurrent sensing device which comprises:(1) a first planar metal foil electrode at one end region of the device; (2) a second planar metal foil electrode at another end region of the device oppositely of the first planar metal foil electrode; (3) a third planar metal foil electrode at an intermediate region of the device; (4) a planar metal foil current-concentrating conductor bridging between the first and second electrodes; (5) a planar sheet of a composition which exhibits PTC behavior and which comprises a crystalline organic polymer and a particulate conductive filler dispersed in the organic polymers the planar sheet having a first major surface and an opposite second major surface; (6) an electrical connector; and (7) a fourth planar metal member of metal foil which is secured to the first major surface of the planar PTC sheet and is spatially separate from the first and second electrodes and conductor; the first and second electrodes and the conductor being different regions of a unitary sheet of metal foil which is secured to the first major surface of the planar PTC sheet, the conductor having a transverse cross-sectional area smaller than a transverse cross-sectional area of each of the first and second electrodes, the third electrode being secured to the second major surface of the planar PTC sheet, and the electrical connector contacting the planar PTC sheet and connecting the third electrode and the fourth metal member.