| US 7,602,269 B2 | ||
| Permanent current switch | ||
| Masaya Takahashi, Hitachinaka (Japan); Kazuhide Tanaka, Hitachi (Japan); and Michiya Okada, Mito (Japan) | ||
| Assigned to Hitachi, Ltd., Tokyo (Japan) | ||
| Filed on Jan. 17, 2007, as Appl. No. 11/654,008. | ||
| Claims priority of application No. 2006-041800 (JP), filed on Feb. 20, 2006. | ||
| Prior Publication US 2007/0194870 A1, Aug. 23, 2007 | ||
| Int. Cl. H01F 7/00 (2006.01); H01F 1/00 (2006.01); H01F 6/00 (2006.01) | ||
| U.S. Cl. 335—216 [335/217; 174/125.1; 361/19; 361/20; 361/21; 361/139; 361/141; 336/155] | 10 Claims |
| 1. A permanent current switch comprising:
a coiled superconducting wire and a winding portion which is wound with a heater wire which switches the superconducting wire
between a superconducting state and a normal conducting state, the superconducting wire being a magnesium diboride superconducting
wire having a high-resistance metal on an outer side and a magnesium diboride superconducting portion on an inner side and
prepared by forming a superconducting metal on a layer between the high-resistance metal and the magnesium diboride superconducting
portion; and
a superconductive connecting section superconductively connected to a lead wire of the superconducting wire and a superconducting
wire for a wiring line, wherein the superconductive connecting section superconductively connects the magnesium diboride superconducting
portion or the superconducting metal with which the magnesium diboride superconducting portion is coated to a superconducting
core portion of the superconducting wire for the wiring line via a low-melting superconducting metal or a low-melting superconducting
alloy,
wherein the lead wire comprises a portion having a Nb tube and a high resistance metal and a portion connected to the superconductive
connecting section without the high-resistance metal.
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