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Ferrite Core Storage Testing Procedure

IP.com Disclosure Number: IPCOM000094857D
Original Publication Date: 1965-Jun-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Gagnon, FL: AUTHOR

Abstract

This five-step testing procedure for ferromagnetic, ferrospinel ferrite cores offers greater flexibility and predictability as to the adaptability of the cores for storage applications. The operational characteristics evaluated are the usual parameters shown on the hysteresis loop in the upper left drawing.

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Ferrite Core Storage Testing Procedure

This five-step testing procedure for ferromagnetic, ferrospinel ferrite cores offers greater flexibility and predictability as to the adaptability of the cores for storage applications. The operational characteristics evaluated are the usual parameters shown on the hysteresis loop in the upper left drawing.

In the first step of the procedure as shown in the flow chart, the read-disturb binary 1 rV1 response is measured. Where the response is above preselected value X1, the core is then directed to station 201. Where response is below preselected value X1 but above preselected value X2, the core is sent to station 203. Where the response is below preselected value X2, the core is directly forwarded to the reject station.

The cores at both stations 201 and 203 are then tested for their write-disturb binary 0 wVz response. The cores with a response above minimum specified requirements are then further tested for their threshold current Io that provides the field to drive the core to the knee of the hysteresis loop. The cores with a wVz response below requirements are forwarded directly to the reject station. Now those cores with the required Io response are shipped to stations 401 and 403, respectively. The cores with a below normal Io response are forwarded to stations 402 and 404, respectively.

At stations 401...404, the switching speed Ts, i.e., the time it takes the core to change the polarity of the magnetic remanence, is...