Improvement of Reliance on Zinc oxide

ZnO Varistor의 신뢰성 향상

  • Cho, Hyun-Moo (Dep. of Electrical Electronic Engineering Seonam Univ.) ;
  • Lee, Sung-Gap (Dep. of Electrical Electronic Engineering Seonam Univ.)
  • 조현무 (서남대학교 전기전자공학부) ;
  • 이성갑 (서남대학교 전기전자공학부)
  • Published : 2004.07.05

Abstract

ZnO varistor ceramics which were fabricated with variation of added of $0.5{\sim}1.0mol%\;Co_3O_4$ sintered at $1150^{\circ}C$. In the specimen added $0.7mol%\;Co_3O_4$, sintered density was $6.03g/cm^3$ and electrical peoperties were superior to any other components. The nonlinear coefficient a was 83, and clamping voltage ratio was 1.35. But, endurence surge current in the specimen added $0.5mol%\;Co_3O_4$ was $7000A/cm^2$, and deviation of varistor voltage was ${\Delta}-3.23%$. As P.C.T and T.C.T environment test were succeed in all specimens, and deviation of varistor voltage in the specimen added $0.6mol%\;Co_3O_4$ was ${\Delta}-0.81%$. All specimens showed a good leakage current property in the High Temperature Continuous Load Test for 1000hr, at $85^{\circ}C$, and variation rate of the varistor voltage was ${\Delta}-2%$.

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