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Cryotron Phase Detector

IP.com Disclosure Number: IPCOM000098083D
Original Publication Date: 1961-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Conroy, ED: AUTHOR

Abstract

The circuit determines if two signals at inputs A and B are in phase. There are two differentiators 10 and 11 and a coincidence detector 12. The A and B signals are respectively differentiated by 10 and 11 and their output is sent to 12. If the outputs from 10 and 11 occur simultaneously, inputs A and B are in phase. If the inputs received by 12 do not occur simultaneously, signals A and B are not in phase.

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Cryotron Phase Detector

The circuit determines if two signals at inputs A and B are in phase. There are two differentiators 10 and 11 and a coincidence detector 12. The A and B signals are respectively differentiated by 10 and 11 and their output is sent to 12. If the outputs from 10 and 11 occur simultaneously, inputs A and B are in phase. If the inputs received by 12 do not occur simultaneously, signals A and B are not in phase.

Each differentiator consists of current source 21 and current collector 22, three paths 25, 26 and 27 connecting source 21 to current collector 22. Cryotrons 30 and 31 are respectively connected in paths 25 and 26. Permanent resistor element 34 is connected in series with current 27. Variable resistor element 35 is connected in series with path 27. Each cryotron 30 and 31 requires two units of current in the control lines, directed in opposition to the current in the gate element. This makes the gate element resistive. Each cryotron 30 has a control line (not shown) with two units of fixed bias current directed in opposition to the current in the gate element. Each cryotron 31 has a control line (not shown) with one unit of fixed bias current directed in opposition to the gate current.

Normally, no current is applied to inputs A and B and to input 65. Hence, current normally flows in path 26 in each differentiator. In differentiator 10, a signal on A makes cryotron 31 resistive and cryotron 30 superconducting, shifting the current from path 26 to path 25. As the current shifts from path 26 to path 25, a current which represents th...