Abstract: A current limiting PTC device (10) has two electrodes (14) with a thin film of electric conducting polymer material (20) disposed between the electrodes, the polymer material (20) having superior flexibility and short circuit performance, where the polymer material contains short chain aliphatic diepoxide, conductive filler particles, curing agent, and, preferably, a minor amount of bisphenol A epoxy resin.

Abstract: A novel multi-layer current limiting PTC polymer device comprising at least two layers of a conductive polymer composition with electrodes attached thereto characterized by having a low contact resistance and a method of producing the same. The invention provides for the selective treatment of portions of the surface of each layer of the conductive polymer composition by at least one of plasma/corona etching and plasma sputtering/plasma spray to create a site for attachment of the electrodes resulting in a low contact resistance. The electrical devices of the invention are particularly useful in circuit protection applications.

Abstract: A novel current limiting PTC polymer device comprising a conductive polymer composition with electrodes attached thereto characterized by having a low contact resistance and a method of producing the same. The invention provides for the selective treatment of portions of the surface of the conductive polymer composition by at least one of plasma/corona etching and plasma sputtering/plasma spray to create a site for attachment of the electrodes resulting in a low contact resistance. The electrical devices of the invention are particularly useful in circuit protection applications.

Abstract: A high voltage current limiting fuse has improved low fault current interruption due to an end-sealed sleeve separating a fusible length from pulverulent sand in a casing of the fuse while permitting venting of gas and vaporized metal plasma due to melting and arcing at the fusible length. The fuse can have one or more fusible elements, of which at least one, preferably each one, is surrounded along at least a selected portion along its length by a polytetrafluoroethylene polymer, fluoroethylene polymer, or derivatives thereof, which can be heat shrinkable or not. The sleeve is sealed so as to allow escape of gases upon arcing from the sleeve but to prevent pulverulent materials from penetrating within the sleeve. The sleeve seals are either melted and crimped together with the fusible element, heat shrunk down onto the fusible element, or taped over the fusible element so as to leave a gap small enough to exclude the pulverulent material while venting gas and plasma.