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High Current Superconducting Switch

IP.com Disclosure Number: IPCOM000035425D
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Gillett, JB: AUTHOR

Abstract

A superconducting line has a limit to the current density it can maintain, determined in part by the magnetic field imposed on it. In the absence of a magnetic field, a large current can be carried with no electrical resistance. If a critical magnetic field is exceeded, the superconductor drops back to a resistive state. Hence, the application of a large enough magnetic field can cause the superconductor to act as a controlled switch.

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High Current Superconducting Switch

A superconducting line has a limit to the current density it can maintain, determined in part by the magnetic field imposed on it. In the absence of a magnetic field, a large current can be carried with no electrical resistance. If a critical magnetic field is exceeded, the superconductor drops back to a resistive state. Hence, the application of a large enough magnetic field can cause the superconductor to act as a controlled switch.

As shown in the figure, a number of parallel superconducting paths are laid on a substrate. These form the controlled path and will carry the very high current which is to be switched. Interlacing them, on the same level if crossovers are available, or on another level, is a serpentine series path of superconducting material arranged such that its current flow on one side of a controlled path is in the opposite direction to its current flow on the other side. As a result of this arrangement, current in the series, or controlling, path produces fluxes which add in the controlled path surrounded by a pair of adjacent series elements. A current of sufficient magnitude in the controlling path will cause the controlled path to cease superconducting.

For efficient operation, it is important that the controlling path also be a superconductor, and remain in the superconducting state at all times. Since there is a high magnetic field associated with the high current in the controlled paths, this would norm...