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:
Jan. 22, 1975
Frederick J Conforti, Aurora, IL (US);
Clifford E Mensing, Glen Ellyn, IL (US);
Pittway Corporation, Northbrook, IL (US);
Abstract
An improved warning device having means for sensing or detecting a predetermined danger or phenomenon has a compensation circuit for the sensing means, including compensating means connected to the sensing means, amplifier means connected to the junction of the sensing and compensating means, and a feed-back circuit connected to the output of the amplifier means and the input of the compensating means for maintaining the output voltage of the amplifier means substantially constant despite slowly occurring changes in the voltage drop across the sensing means. Means, such as a resistance-capacitance network, is provided in the feedback circuit for rendering the amplifier means non-responsive to slowly occurring changes in the voltage drop across the sensing means and for maintaining the amplifier means responsive to rapidly occurring changes in the voltage drop across the sensing means, as occurs in the presence of the danger or phenomenon to be detected.