Importance

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Abstract

The invention relates to a type-II overvoltage protection device having a varistor and a protective element, wherein the protective element has a first contact for connecting to a first potential of a supply network and a second contact that is connected to a first contact of the varistor, wherein the varistor further comprises a second contact for connecting to a second potential of a supply network, wherein the protective element has a fuse element that connects the first contact and the second contact of the protective element, wherein the protective element further comprises a third contact that is connected to the second contact of the varistor and is arranged so as to be near to but electrically insulated from the fuse element, wherein the fuse element has a constriction in the proximity of the neighboring contact, with the constriction being embodied such that the fuse element has an electrically conductive fluxing agent in the proximity of the constriction, with the fluxing agent having a lower fusion point than the fuse element itself, so that pulses corresponding to a load below the type-II rating do not result in a lasting change in the constriction, wherein the constriction, in conjunction with the fluxing agent, is dimensioned such that pulses corresponding to the limit range of the type-II rating result in the fusing of the fluxing agent into the fuse element, and wherein pulses corresponding to a load that is stronger and/or of greater duration than the type-II rating of the varistor result in the immediate disconnection of the fuse element.

First Claim