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:
Dec. 09, 1986
Filed:
Jun. 05, 1985
Applicant:
Inventor:
Richard C Boyle, Springfield, PA (US);
Assignee:
System Development Corporation, McLean, VA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340661 ; 307236 ; 307311 ; 324133 ; 328118 ; 330 59 ; 340664 ;
Abstract
A circuit for monitoring the status of electrical signals, such as those present on the control and data lines of an RS-232 interface, includes a single operational amplifier and a dual-color LED indicator. The electrical characteristics of the LED's form a significant part of the circuit parameters. The monitor design provides a predetermined circuit input impedance and positive/negative switching thresholds to effect the selective illumination of the LED's.