| 摘要 |
PROBLEM TO BE SOLVED: To provide a resistor for power use having a large heat capacity per unit volume, an appropriate resistance, and a small temperature change rate over a wide temperature range by suppressing the resistance drop caused by an electric field and resistance fluctuation caused by the temperature within tolerances by connecting a sintered body having a positive temperature coefficient of resistance to another sintered body having a negative temperature coefficient of resistance. SOLUTION: A sintered body having a positive temperature coefficient of resistance contains zinc oxide as a main component and titanium and chromium as additional ingredients, with the content of the titanium being adjusted within a range from about 0.5 mol.% to 20 mol.% expressed in terms of titanium oxide and that of the chromium being adjusted within a range from about 0.5 mol.% to 10 mol.% expressed in terms of chromium oxide. Another sintered body having a negative temperature coefficient of resistance contains zinc oxide as a main component and titanium and copper as accessory ingredients, with the content of the titanium being adjusted within a range from about 0.5 mol.% to 20 mol.% expressed in terms of titanium oxide and that of the copper being adjusted within a range from about 0.001 mol.% 0.5 mol.% expressed in terms of cuprous oxide.A resistor is obtained by connecting the two kinds of sintered bodies each other. The densities of sintered bodies are adjusted to about 5.30 g/cm<3> or higher. Therefore, the size of a circuit breaker incorporating the resistor can be reduced. |
