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:
Apr. 10, 1979
Filed:
Jun. 20, 1977
Applicant:
Inventors:
Robert B Enemark, Duxbury, MA (US);
Paul S Richtarcsik, Whitman, MA (US);
Assignee:
American District Telegraph Company, Jersey City, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ; G08B / ;
U.S. Cl.
CPC ...
340636 ; 340630 ; 250574 ;
Abstract
A battery powered smoke detector includes a battery powered discriminator circuit which periodically senses the chemistry of the battery represented by its volt-ampere output and internal impedance. An external impedance comparable to the alarm circuit load on the battery is connected in parallel with the battery such as to trigger an alarm when the battery energy delivered through the impedance approaches a level inadequate to drive the alarm.