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. 01, 1980
Filed:
Jul. 10, 1978
Francis T Ogawa, Lakewood, CO (US);
Emerson Electric Company, St. Louis, MO (US);
Abstract
A self-monitoring ion chamber type combustion products detection apparatus operable to generate perceptibly different output signals indicative of, respectively: the apparatus is being tested; the condition of the apparatus is normal; an alarm condition is detected; an apparatus malfunction is detected; and, a low power supply voltage is detected. The impedance of the ion chamber of the apparatus varies as a function of the degree of combustion products in the atmosphere being monitored and this change in impedance produces a variation in the output voltage of the ion chamber which is used by the apparatus to produce an alarm signal. In generating different output signals, the apparatus employs test, alarm, fault and low power supply reference voltages. An oscillator circuit is selectively driven by one or more substantially constant current sources to produce output pulses having predetermined frequencies which are utilized in producing at least some of the perceptibly different output signals. A battery may be used to provide power for the apparatus, and the perceptibly different output signals are preferably produced as visible light or audible sound signals.