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:
Sep. 03, 1985
Filed:
Apr. 15, 1983
Stanley S Dederich, Naperville, IL (US);
George A Schoenfelder, Downers Grove, IL (US);
William M Koster, Bartlett, IL (US);
Pittway Corporation, Aurora, IL (US);
Abstract
A battery-powered photoelectric smoke detector periodically samples the air in a smoke chamber. A manually-operated test button is provided for simulating smoke to test the device. The sampling frequency is determined by a first resistance. A frequency changing circuit includes a test switch, the movable contact of which is coupled to the test button and is responsive to operation thereof for connecting it parallel with the first resistance the series combination of a diode and a second resistance for increasing the sampling frequency. Means are provided for back-biasing the diode to disable the frequency changing circuit when the detector detects smoke.