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:
Mar. 12, 1991
Filed:
Jan. 12, 1989
Michael D Durkin, Austin, TX (US);
Dell Corporate Services Corporation, Austin, TX (US);
Abstract
An electronic digital computer has a warning facility for indicating activity and operation, or lack of same, of the central processor in the system. It is done by providing a signal indicative of continuing operation of the central processor to activate an indicator circuit. The indicated circuit utilizes an RC circuit for maintaining a high level through a high comparator when the processor is operational. When the central processor becomes non-operational, the capacitor discharges to a point where a low comparator responds, causing the capacitor to begin charging to its high value. The associated circuits, using this feature, maintain an LED in the active stage until such time as there is no signal indicating continuing operation of the central processor, at which time the LED begins an approximate 50% duty cycle resulting in a blinking indicator.