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Self-Replacement Circuit for Cryogenic Systems

IP.com Disclosure Number: IPCOM000097731D
Original Publication Date: 1961-May-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 3 page(s) / 49K

Publishing Venue

IBM

Related People

Rutledge, JD: AUTHOR

Abstract

An operating cryogenic circuit together with a number of identical spare circuits are shown. Upon a failure occurring in the operating circuit, power is removed from it and is automatically applied to the next succeeding spare circuit. This then becomes the operating circuit. Such switching action automatically continues until a failure occurs in the last spare circuit, at which time an alarm device is actuated. The additional circuitry shown above is automatically effective at the cryogenic operating temperature of 269 degrees C below room temperature.

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Self-Replacement Circuit for Cryogenic Systems

An operating cryogenic circuit together with a number of identical spare circuits are shown. Upon a failure occurring in the operating circuit, power is removed from it and is automatically applied to the next succeeding spare circuit. This then becomes the operating circuit. Such switching action automatically continues until a failure occurs in the last spare circuit, at which time an alarm device is actuated. The additional circuitry shown above is automatically effective at the cryogenic operating temperature of 269 degrees C below room temperature.

Circuit power is normally applied to operating circuit A from a constant current source coupled to a pair of terminals P+ and P-. Current flows in opposite directions through a pair of controls associated with a cryotron 1A, maintaining its gate superconducting. Further, this same current also flows through a pair of controls associated with a cryotron 3A. Here, however, the currents flow in the same direction, switching the gate of 3A resistive.

As a result of the circuit power current flow, current from an auxiliary power supply CPS is directed through the superconducting gate of 1A, and thence through the control of cryotrons 5A, the gate of cryotron 6A, and the control of cryotrons 7A and 8A. The resistive gates of 7A and 8A effectively isolate the spare circuits from the main power source.

Upon the occurrence of a failure in the operating circuit, as a result of a short or open circuit, current flow through the controls of 1A becomes unbalanced, switching the gate of 1A resistive. Simultaneously, this current unbalance is also applied to the gate of 3A. This, together with the bias current flow through a third control, allows the gate of 3A to become superconducting. This combined switching action is effective to shift the current from CPS from its quiescent path to a now...