Patent ID: 8816812

Claim:
A varistor fuse element, comprising: a cylindrical fuse including an electrically insulating fuse body that defines a longitudinal passage, wherein first and second electrically conductive fuse contacts are located on opposite ends of the fuse body, and wherein the longitudinal passage includes an arc extinguishing material; a cylindrical varistor that is located in the longitudinal passage, that includes a varistor body having a resistance that is dependent on voltage, and that is serially electrically connected to the fuse with an electrically conductive first varistor electrode located on an external surface of the varistor body and electrically connected to the first fuse contact, and an electrically conductive second varistor electrode located on an internal surface of the varistor body such that the first and second varistor electrodes are separated by the varistor body; and an electrically conductive melting member connecting the second fuse contact and the second varistor electrode in order to connect the first and second fuse contacts, wherein the melting member includes a weak portion having a pre-determined cross-section that is operable to melt and interrupt the connection between the first and second fuse contacts when the fuse is electrically overloaded.