Overvoltage suppressor having a spark gap in air

摘要

In the case of an overvoltage suppressor having a parallel-connected spark gap in air, in order to reduce the design and manufacturing cost for that spark gap in air which is assigned to the second electrode, the suppressor (22) is enclosed by a cylindrical metal casing (28). One edge (19) of this metal casing makes contact with the first electrode (3) of the suppressor, while the other edge (14) is bent inwards and grips the auxiliary electrode (27), which is placed on the second electrode (25) with an insulating washer (26) being interposed. The external diameter of this auxiliary electrode (27) is larger than the external diameter of the second electrode (25). In order to centre the suppressor (22) in the metal casing (28), the distance between the suppressor and the metal casing is less, at at least three circumferential points, than the required radial safety distance between the metal casing and the second electrode. This can be achieved, for example, by means of a plurality of depressions (30), which are in the form of spots and are arranged distributed uniformly on the circumference, in the metal casing, or else by means of an annular constriction (29). <IMAGE>