Patent ID: 7433169
Filing Date: 2008-10-07
Classification: H01C,H01H

Abstract:
1. An overvoltage protection device comprising: a) first and second electrically conductive electrode members; b) a varistor member formed of a varistor material and electrically connected with each of the first and second electrode members; and c) an electrically conductive, meltable member, wherein the meltable member is responsive to heat in the device to melt and form a current flow path between the first and second electrode members through the meltable member; wherein the varistor member is adapted to generate heat from ohmic losses in the varistor member when the varistor member is in an end of life mode, and the meltable member is responsive to heat generated from ohmic losses in the varistor member when the varistor member is in its end of life mode to melt and form the new current flow path to prevent catastrophic destruction of the device due to thermal runaway.