Varistor including an electrode with jag portion forming a pole and lightning including such a varistor

The varistor (30) has a conductive plate (84) forming a contact electrode with a non-linear electrical resistance block (80). The plate is arranged on a main face i.e. base (82), of the block, and includes a protruding portion forming one connection pole (34). An electrically insulating coating is applied to an assembly formed by the main face and the plate. The protruding portion emerges from the coating and comprises a braze surface for electrical connection. The braze surface extends above the coating. The protruding portion is connected to the plate over half of a perimeter of the plate. Independent claims are also included for the following: (1) a protective device for protecting an electric installation from voltage surges (2) a cartridge comprising a case.