To provide a current limiting device which has characteristics suitable for a large rating and a high cut-off capacity such as the secure current limiting operation, a low final temperature and the quick restoration to a low resistance after the cut-off and which is made of vanadium oxide system ceramic containing additive which has a positive resistance-temperature coefficient and changes the temperature coefficient of a resistivity significantly.
A main resistor unit 1 consisting of a cylindrical transition resistor unit 3 made of vanadium oxide system ceramic whose composition is expressed by a formula: (V1-xAx)2O3 (where 0.001 ≤x≤0.02 and A denotes at least one among Al, Cr and Sc) and molybdenum electrodes 5 which are soldered to both the ends of the cylindrical transistion resistor unit 3 with solder foils 4 and a commutation resistor 2 made from a stainless steeel wire 6 whose resistance is 45mΩ are connected in parallel to each other.
YOSHIZAWA TOSHIYUKI
KUNIHARA KENJI
