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Ferrite Pole Drive Structure

IP.com Disclosure Number: IPCOM000087628D
Original Publication Date: 1977-Feb-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Voegeli, O: AUTHOR

Abstract

Bubble memory modules containing ferrite pole structures, such as shown in Fig. 1, have been previously described where 2 is a ferrite ring for flux closure, 4 is a ferrite pole, 6 is a coil winding and 8 is a memory chip. The disadvantages of this structure are the low efficiency and distortion of the field uniformity caused by flux-shunting between the X and Y pole pieces, as well as large coil losses due to large pole piece widths.

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Ferrite Pole Drive Structure

Bubble memory modules containing ferrite pole structures, such as shown in Fig. 1, have been previously described where 2 is a ferrite ring for flux closure, 4 is a ferrite pole, 6 is a coil winding and 8 is a memory chip. The disadvantages of this structure are the low efficiency and distortion of the field uniformity caused by flux-shunting between the X and Y pole pieces, as well as large coil losses due to large pole piece widths.

An improved ferrite pole structure which overcomes the aforementioned disadvantages is shown in Fig. 2 (top view). This structure contains horizontal and vertical drive bars 11 and 12, respectively, separating the bubble chips 20. Around each drive bar are wound several turns of a current conductor forming horizontal and vertical drive coils 31, 32, 33 and 41, 42, 43, respectively. The horizontal coils are activated by the X-driver in unison, and the vertical coils 90 degrees out of phase by the Y-driver. The coils are wound or interconnected such that opposing magnetic inductance is produced in successive bar segments, as is depicted by the arrow through each coil. Activation of the vertical coils thus causes the horizontal bars to have a magnetic potential of alternate sign in adjacent bars as is indicated by the +, -signs. This magnetic potential configuration produces, within each chip area, a uniform drive field in the Y-direction, as is indicated by arrows on the chips.

Fig. 3 is an exploded cross-...