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Angelfish Circuits for Cylindrical Magnetic Domains

IP.com Disclosure Number: IPCOM000074283D
Original Publication Date: 1971-Apr-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Almasi, GS: AUTHOR [+4]

Abstract

Conventional "angelfish" circuits use permalloy guide rails and triangular permalloy pieces located on a magnetic sheet in which domains exist. Modulation of the bias field H(z) causes the domains to alternately expand and contract and to move in the direction of the triangular pieces. Propagation in this manner is simple but slow due to the fact that the inductance of the main bias coils producing H limits the rise time of the drive system.

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Angelfish Circuits for Cylindrical Magnetic Domains

Conventional "angelfish" circuits use permalloy guide rails and triangular permalloy pieces located on a magnetic sheet in which domains exist. Modulation of the bias field H(z) causes the domains to alternately expand and contract and to move in the direction of the triangular pieces. Propagation in this manner is simple but slow due to the fact that the inductance of the main bias coils producing H limits the rise time of the drive system.

In the structure shown in Figs. A and B, one of the conventional permalloy guide rails is replaced by a copper strip line having a permalloy keeper thereon. Modulation of the bias field H(z) is produced by currents of one polarity in the copper strip line. Since the inductance of the strip line is much smaller than that of the bias coils used to produce H(z), the rise time of the drive system will no longer limit the speed of domain propagation. Further, since the strip line need only produce fields of 5 or 6 Oe, the current levels (thus power dissipation) will be low in comparison with the current used to propagate domains in conventional conductor loop patterns.

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