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US4734883A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic bubble memory purge and verification system

Assignee: LIBRASCOPE Corp A CORP OF DELAWARE
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Filing: 1985-05-10
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Granted: 1988-03-29
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Expires: 2005-05-10
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Abstract

Abstract An arrangement for purging a magnetic bubble memory and providing a visible purge verification utilizes the thermal compensation Z-axis coil for providing a purge field. A power supply, purge switch and current sensitive circuit interrupter are connected across the thermal compensation coil. When the switch is closed, a surge of relatively high current many times greater than that required for thermal compensation is applied to the coil. Accordingly, the bubbles in the memory will completely disappear. The circuit interrupter is used to halt the purge current once it exceeds the required purge value. This protects the thermal compensation winding and also provides a visual verification that a purge pulse has occurred.

Inventors

  • 👤 Bruce C. Perkin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 15:31
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/085; G11C19/0858

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 136 words
In combination with a bubble memory having a Z-axis thermal compensation coil, an arrangement for erasing the contents of said memory comprising: a source of electrical power having two output terminals; means for connecting said terminals to one side of a normally open double pole single throw switch; a diode bridge having a pair of input terminals and a pair of output terminals; means for connecting the second side of said switch to said diode bridge input terminals; means for connecting a first of said diode bridge output terminals to a first end of said coil; a current sensitive circuit interrupter; means for connecting the second of said diode bridge output terminals to a first side of said interrupter; and means for connecting the second side of said interrupter to the second end of said coil.
Claim 2
Dependent Claim 136 words
In combination with a bubble memory having a Z-axis thermal compensation coil, an arrangement for erasing the contents of said memory comprising: a source of electrical power having two output terminals; means for connecting said terminals to one side of a normally open double pole single throw switch; a diode bridge having a pair of input terminals and a pair of output terminals; means for connecting the second side of said switch to said diode bridge input terminals; means for connecting a first of said diode bridge output terminals to a first end of said coil; a current sensitive circuit interrupter; means for connecting the second of said diode bridge output terminals to a first side of said interrupter; and means for connecting the second side of said interrupter to the second end of said coil.
Claim 3
Dependent Claim 20 words
The arrangement according to claim 1 further including means for providing a visible indication of the condition of said interrupter.

References Cited (Backward Citations)

US3460116A Cited
US3503054A Cited
US3602911A Cited
US3714640A Cited
US3711841A Cited
US3744042A Cited
US4068219A Cited
US4400809A Cited
US4675513A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-29 1991-09-28 1992-03-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-29 1995-09-28 1996-03-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-29 1999-09-28 2000-03-29 $7700.00 Window Closed / Lapsed

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