| 摘要 |
PURPOSE:To make it possible to cut off a current at an appropriate time with respect to changes in the current flowing through or in temperature or magnetic field applied to a superconductive wire used in a circuit by attaching a ferromagnetic body to a movable contact point of a superconductive material and arranging a magnet in the direction of movement of the movable contact point. CONSTITUTION:A superconductive movable contact point 3 is constituted with a superconductive material of the same characteristic with that of a superconductive wire 4. If a critical current becomes smaller than a flowing current due to changes in the temperature or magnetic field surrounding the superconductive material, the superconductive wire 4 and the superconductive movable contact point 3 shift to normal conductors. While the superconductive movable contact point 3 has been repulsing a magnet 1 under the superconductive condition due to the Meissner effect, when the repulsive force is lost due to the breakage of the superconductive condition, the superconductive movable contact point 3 separates from the super conductive wire 4 caused by the force attracting an iron piece 2 attached to the contact point 3 and becomes in a condition of break. This makes it possible to cut off a current at an appropriate time with respect to changes in the current flowing through or in temperature or magnetic field applied to the superconductive wire 4. |
