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:
Oct. 18, 1977
Filed:
Nov. 05, 1975
Gerald D Smith, Indianapolis, IN (US);
Sammie S Witte, Indianapolis, IN (US);
Carson Manufacturing Company, Indianapolis, IN (US);
Abstract
A circuit for switching between two signals of different frequency, such as 'wail' and 'yelp' of an electronic siren, by switching between different capacitive values in a multivibrator circuit. A monostable switch couples a reference level voltage to an integrated flip-flop circuit. The integrated circuit receives a reference level pulse when the monostable switch is closed and supplies a switching voltage to a transistor circuit. The transistor circuit places capacitances in parallel to change the time constant of the multivibrator circuit and also to change the characteristics of wave-shaping circuitry coupled to the multivibrator circuit. A reference level circuit accepts either of two voltage levels and provides a reference level voltage.