The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 2002
Filed:
Oct. 23, 1998
ABB Research Ltd, Zurich, CH;
Abstract
Ceramic high-temperature superconductors ( ) which are intended to be used as current limiters in alternating-current lines should have a bypass layer ( ) whose electrical resistivity is increased by more than 10 times with respect to that of a pure noble-metal bypass layer. In order to achieve this, the noble-metal bypass layer ( ) of the high-temperature superconductor ( ), preferably of silver, is alloyed with a base metal, preferably Pb or Bi or Ga, by a thermal treatment. The ratio of the bypass layer thickness (d ) of the noble-metal bypass layer ( ) to the superconductor layer thickness (d ) is adjusted to <1/5. A base-metal bypass layer ( ) of steel whose electrical resistivity is in the range between 10 &mgr;&OHgr;×cm and 100 &mgr;&OHgr;×cm at 77 K is soldered on or applied under isostatic pressure over the noble-metal-containing bypass layer ( ). The noble-metal bypass layer thickness d and the base-metal bypass layer thickness d are to be chosen so that the ratio &rgr;2/d is >0.5×&rgr;3/d , where &rgr;2 and &rgr;3 are the electrical resistivity of the noble-metal-containing bypass layer ( ) and the base-metal bypass layer ( ′), respectively.