Abstract: An average size of ZnO particles which are three dimensionally connected and serve as primary component of a non-linear resistor, is adjusted to be within a range of 5 .mu.m to 10 .mu.m. The non-linear resistor is consisted of:______________________________________ Bi.sub.2 O.sub.3 0.25 to 1.0 mole %; Sb.sub.2 O.sub.3 0.5 to 2.0 mole %; Co.sub.2 O.sub.3 0.25 to 1.0 mole %; MnO.sub.2 0.25 to 1.0 mol %; Cr.sub.2 O.sub.3 0.1 to 1.0 mol %; NiO.sub.2 0.1 to 1.0 mol %; SiO.sub.2 0.25 to 2.0 mole %; and ZnO remainder for 100 mol %.

Abstract: The invention disclosed a vacuum type electric circuit interrupter comprising a highly evacuated envelope which includes at least one metallic tube made of the magnetic material or the ferromagnetic material, a pair of relatively movable contacts disposed within said envelope in a location and means for eliminating the magnetodistortion of said metallic tube. This means comprises a magnetic flux generating member for supplying the magnetic flux to said metallic tube. The noise generated from the vacuum circuit interrupter is, accordingly, eliminated by means of a magnetic field applying member for applying previously the magnetic field to said metallic tube or by increasing the magnetic reluctance of the metallic tube.

Abstract: .[.The invention disclosed a vacuum type electric circuit interrupter comprising a highly evacuated envelope which includes at least one metallic tube made of the magnetic material or the ferromagnetic material, a pair of relatively movable contacts disposed within said envelope in a location and means for eliminating the magnetodistortion of said metallic tube. This means comprises a magnetic flux generating member for supplying the magnetic flux to said metallic tube. The noise generated from the vacuum circuit interrupter is, accordingly, eliminated by means of a magnetic field applying member for applying previously the magnetic field to said metallic tube or by increasing the magnetic reluctance of the metallic tube..]. .Iadd.A vacuum type electric circuit interrupter comprises a highly evacuated envelope including at least one metallic tube made of magnetic or ferromagnetic material and a pair of relatively movable contacts disposed within the envelope.