| 摘要 |
PROBLEM TO BE SOLVED: To provide a permanent current switch by which a loss in a closed state is small and a transition from the closed state to an open state is achieved for a short time. SOLUTION: The permanent current switch 18 is connected in parallel with a superconducting coil 16 with a superconductor wound up, electrically comes to the open state displaying high impedance when the superconducting coil 16 is excited, then comes to the closed state changed into a low impedance state after it reaches a rated current to constitute a permanent current loop 17 with the superconducting coil 16, and electrically becomes the open state displaying high impedance at its subsequent demagnetizing time, wherein the switch is constituted to include switch portions (18a, 18b) formed by the superconductor to be lower in inductance than the superconducting coil, and a current supply means (19, 20) to supply a current that permits the switch portions to transit to a normal conduction when the superconducting coil is demagnetized. COPYRIGHT: (C)2005,JPO&NCIPI |
