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:
Jan. 13, 1976
Filed:
May. 31, 1974
Applicant:
Inventors:
L Dennis Shapiro, Lincoln, MA (US);
Aaron A Galvin, Lexington, MA (US);
Assignee:
American District Telegraph Company, New York, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340411 ; 340214 ; 343 177 ;
Abstract
For use in an intrusion alarm system, an on-line test circuit operative for the continuous supervision of system operation without affecting normal operation thereof. The transmitted signal is frequently modulated at a low rate to produce a detectable change in reflected energy sensed by sub-Doppler processing circuitry and operative to produce a failure indication in the absence of such sub-Doppler signal.