The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 1992
Filed:
Feb. 19, 1991
NGK Insulators, Ltd., Aichi, JP;
Abstract
An excellent voltage non-linear resistor for use in a gapped lightning arrestor having a composition containing 1 0.5-1.2 mole % of bismuth oxide calculated as Bi.sub.2 O.sub.3, 2 0.3-1.5 mole % of cobalt oxide calculated as Co.sub.2 O.sub.3, 3 0.2-0.8 mole % of manganese oxide calculated as MnO.sub.2, 4 0.5-1.5 mole % of antimony oxide calculated as Sb.sub.2 O.sub.3, 5 0.1-1.5 mole % of chromium oxide calculated as Cr.sub.2 O.sub.3, 6 0.6-2.0 mole % of silicon oxide calculated as SiO.sub.2, 7 0.8-2.5 mole % of nickel oxide calculated as NiO, 8 0.004-0.04 mole % of aluminum oxide calculated as Al.sub.2 O.sub.3, 0.0001-0.05 mole % of boron oxide calculated as B.sub.2 O.sub.3 , 10.circle. 0.001-0.05 mole % of silver oxide calculated as Ag.sub.2 O, and 11.circle. the rest of zinc oxide, 12.circle. a limited current of 250-350 V/mm at a current density of 0.1 A/cm.sup.2 calculated per unit thickness of the sintered resistor, 13.circle. a limited current ratio of V.sub.0.1A /V.sub.0.1mA of 1.2-1.7 at current densities of 0.1 A/cm.sup.2 and 0.1 mA/cm.sup.2, and 14.circle. a deterioration rate of limited current of not more than 3% at a current density of 0.1 A/cm.sup.2 before and after applying twice a lightning surge current (4/10 .mu.s wave form) of 5 KA/cm.sup.2 per unit surface area.