Metal oxide resistor, power resistor, and power circuit breaker
AssigneesKabushiki Kaisha Toshiba, Toshiba Tungaloy Co., Ltd.
InventorsMotomasa Imai, Naoki Shutoh, Katsuyoshi Oh-Ishi, Fumio Ueno, Hideo Ohkuma, Yuji Katsumura, Masaki Kobayashi, Toshiyuki Takahashi
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Abstract
A metal oxide resistor for suppressing variations in resistivity in use in an atmosphere at a high temperature or humidity. Such a metal oxide resistor includes a sintered body in which carbon particles having an average grain size of 1 .mu.m or less exist in the grain boundaries of metal oxide particles in an amount of 0.05 to 3 wt %, and electrodes formed on at least two opposing surfaces of the sintered body.
Claims30
A metal oxide resistor comprising:
- a sintered body in which carbon particles having an average grain size of not more than 1 .mu.m exist in a grain boundary of metal oxide particles in an amount of 0.05 to 3 wt %;
- and
- electrodes formed on at least two opposing surfaces of said sintered body.
A power resistor comprising:
- a sintered body in which carbon particles having an average grain size of not more than 1 .mu.m exist in a grain boundary of metal oxide particles in an amount of 0.05 to 0.8 wt %;
- and
- electrodes formed on at least two opposing surfaces of said sintered body.
A power circuit breaker comprising:
- main switching means arranged on a current path;
- auxiliary switching means connected to said current path parallelly with respect to said main switching means and turned on before said main switching means is turned on;
- and
- a closing resistor unit connected in series with said auxiliary switching means and incorporating a resistor having a sintered body and electrodes formed on two opposing surfaces of said sintered body, said sintered body having a structure in which carbon particles having an average grain size of not more than 1 .mu.m exist in a grain boundary of metal oxide particles in an amount of 0.05 to 0.8 wt %.
Dependencies are inferred from the claim text.