The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 1984
Filed:
Jul. 10, 1981
Applicant:
Inventors:
Assignee:
Fanuc Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C / ; H02M / ;
U.S. Cl.
CPC ...
365-1 ; 363 21 ;
Abstract
In a power source device for a bubble memory unit consisting of a bubble memory part and a control part, a controlling supply voltage to be applied to both the bubble memory part and the control part is produced by a power source circuit based on a pulse width modulation system. The power source circuit is provided with a circuit which can expand the signal pulse width in excess of its upper-limit value during the ordinary voltage control. When the controlling supply voltage has become lower than a predetermined value, the pulse width is expanded so that the refresh operation may be perfectly executed when the power source device for the bubble memory unit is turned off.