Bruce C Perkin

US Patent:

49319906, Jun 5, 1990

Filed:

Nov 19, 1987

Appl. No.:

7/122828

Inventors:

Bruce C. Perkin - Tujunga CA

International Classification:

G11C 1908

US Classification:

365 1

Abstract:

An economical circuit arrangement permits disruption, during a nuclear event or single event upset, of operation in portions of a bubble memory system and in a computer connected thereto while maintaining integrity of data stored in the bubble memory. Only critical portions of the bubble support circuits are radiation hardened, and a nonstop logic circuit is provided to continue operation during a nuclear event and to conclude any memory access cycles already in progress at the beginning of the event. Spurious (ionization induced) drive pulses are distinguished from actual pulses. A nuclear event detector generates an output pulse during the event and a delay is provided in a path of the pulses in the critical circuit portions. The delay is greater than the duration of the output pulse of the detector so that pulses arriving after the detector pulse are ignored.

US Patent:

47348836, Mar 29, 1988

Filed:

May 10, 1985

Appl. No.:

6/732780

Inventors:

Bruce C. Perkin - Tujunga CA

Assignee:

The Singer Company - Stamford CT

International Classification:

G11C 1908

US Classification:

365 1

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.