Abstract: A current limiting device comprises at least two electrodes; an electrically conducting composite material between the electrodes; interfaces between the electrodes and electrically conducting composite material; an inhomogeneous distribution of resistance at the interfaces whereby, during a high current event, adiabatic resistive heating at the interfaces causes rapid thermal expansion and vaporization and at least a partial physical separation at the interfaces; and a structure for exerting compressive pressure on the electrically conducting composite material, wherein the electrically conducting composite material comprises at least one polymer matrix and at least one conductive filler.

Abstract: The overvoltage suppressor contains two connecting fittings (1, 2), which are spaced apart from one another along an axis (z) and between which at least one cylindrical varistor element (8) is arranged. The connecting fittings (1, 2) and the at least one varistor element (8) are braced with respect to one another, forming a contact force, to form a mechanically robust active part of the overvoltage suppressor. The active part is sheathed by a molded housing made of insulating material. In each case one material cutout is formed in each of the two connecting fittings (1, 2) with a section (15, 16) which runs essentially transversely with respect to the axis (z), is designed in the form of a slot and extends from the outer surface of the fitting (1, 2) to beyond the axis (z).

Abstract: A current limiting device has an electrically conductive composite material, an inhomogeneous distribution of resistance structure comprises a conducting filler, and at least two electrodes. At least one of the electrodes is a flexible electrode to maintain contact between the electrode and the composite material, regardless of the consumption of the composite material during a high current condition.