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Transformer Coupled Power Supply for Josephson Tunneling Logic Circuits

IP.com Disclosure Number: IPCOM000082154D
Original Publication Date: 1974-Jun-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Anacker, W: AUTHOR [+2]

Abstract

Fig. 1 shows the transformer coupling of power into logic circuits employing Josephson tunneling gates. In Fig. 1 a string of primary winding 1 is shown, each of which is inductively coupled via a transformer secondary 2 to a loop comprising two Josephson tunneling gates 3,4; one of which is utilized for performing logic functions and is shunted by a pair of transmission lines 5,6 which are terminated by resistors R and the other of which is utilized for the purpose of resetting.

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Transformer Coupled Power Supply for Josephson Tunneling Logic Circuits

Fig. 1 shows the transformer coupling of power into logic circuits employing Josephson tunneling gates. In Fig. 1 a string of primary winding 1 is shown, each of which is inductively coupled via a transformer secondary 2 to a loop comprising two Josephson tunneling gates 3,4; one of which is utilized for performing logic functions and is shunted by a pair of transmission lines 5,6 which are terminated by resistors R and the other of which is utilized for the purpose of resetting.

Referring to Figs. 1 and 2, a current pulse, I(1), is supplied to the string of primary windings 1. Since the loops are superconducting, circulating currents I(2)A and I(2)B are set up in the logic circuits otherwise identified in Fig. 1 as circuits A and B. If the control current I(j)A is not sufficient to switch the Josephson device 4 associated with circuit A, the circulating current, I A, subsides at the end of pulse I(1) since no flux has entered the loop associated with logic circuit A. If the control current I(2)B is sufficient to switch Josephson device 4 associated with logic circuit B, it switches to the gap voltage V(1)B causing an output current to flow through the terminating resistor R associated with circuit B.

The superconductivity of the loop associated with logic circuit B is now interrupted and flux enters the loop. The loop current subsides with a time constant of T = L/R, where L is the loop inductance and...