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Browse Prior Art Database

Core Switching With Shortened Drive Pulses

IP.com Disclosure Number: IPCOM000095649D
Original Publication Date: 1964-Apr-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

DiMarco, HA: AUTHOR [+2]

Abstract

The read cycle of square-loop ferrite cores can be materially reduced, while still maintaining a One/Zero ratio in excess of three, by optimizing the core for maximum One/Zero ratio without regard to coincident current switching time.

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Core Switching With Shortened Drive Pulses

The read cycle of square-loop ferrite cores can be materially reduced, while still maintaining a One/Zero ratio in excess of three, by optimizing the core for maximum One/Zero ratio without regard to coincident current switching time.

Drawings A, B and C each depict a plot of three basic parameters, undisturbed 1 (uV1), disturbed 1 (rV1), and disturbed 0 (wVz) for a series of ferrite cores under different operations. Also, to provide a reference, the drive pulse Id, i.e., the total current applied to switch a core, is given. The waveform for the uV1 is obtained by coincident current selection techniques. Waveforms rV1 and wVz are for a 1 and 0, respectively, which have been selectively disturbed by the application of a series of pulses of slightly higher amplitude than used in the conventional coincident selection techniques to obtain the undisturbed 1 or an undisturbed 0.

Drawing A shows a plot of the parameters for a typical, nonoptimized ferrite core subjected to a drive pulse of sufficient duration to substantially, fully switch it. The One/Zero ratio for both the disturbed 1 and undisturbed 1 conditions exceeds three.

Drawing B shows a plot of the parameters for the same nonoptimized core. However, the duration of the coincident current drive pulse has been reduced approximately fifty.percent bringing the One/ Zero ratio to a value below three. Such a core response is generally not satisfactory due to the inability...