Patent ID: 6124780
Filing Date: 2000-09-26
Classification: H01C

Abstract:
A current limiting device comprising:at least two electrodes;an electrically conductive composite material disposed between the at least two electrodes;a first interface between the composite material and a first electrode, and a second interface between the composite material and a second electrode; andan inhomogeneous distribution resistance structure at the interfaces whereby, during a high current event, adiabatic resistive heating of the composite material at the interfaces causes rapid thermal expansion and vaporization of the composite material and separation of the electrodes from composite material and separations within the composite material proximate the interface so the resistance of the current limiting device increases;wherein said electrically conductive composite material comprises:at least one polymeric matrix material and at least one electrically conductive material, and the at least one polymeric matrix material comprises:at least one epoxy; andat least one silicone containing material, wherein the polymeric material matrix comprises a mixture comprising generally equal weights of two epoxy-functionalized siloxanes: 1,1,3,3-tetramethyl-1,3-bis-((2-oxabicyclo (4.1.0) hept-3-yl)-ethyl)disiloxane and polydimethylsiloxane terminated with ethyl-2-(7-oxabicyclo (4.1.0) hept-3-yl) groups.