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:
Aug. 18, 1987
Filed:
Dec. 19, 1985
George Kufta, Glenview, IL (US);
David S Tait, Addison, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
A TV SAP/stereo audio system includes a DC switch for selectively coupling the output of a stereo decoder and the output of a SAP detector to a stereo amplifier. A DC voltage, representative of the SAP carrier level, is developed and applied to a pair of threshold transistors. The lower threshold transistor is driven conductive when the DC voltage is below a first voltage and the upper threshold transistor is driven conductive when the DC voltage is above a second voltage. The threshold voltages are established by a pair of voltage dividers. A SAP control transistor is coupled to the collectors of the threshold transistors and is driven conductive when either threshold transistor is in conduction. The SAP control transistor is connected to the DC switch and prevents coupling of the SAP detector output to the stereo amplifier when it is conducting. A stereo cutoff transistor is coupled to the SAP control transistor for enabling the DC switch to couple the output of the stereo decoder to the stereo amplifier when a SAP mode is selected by a selector switch and the SAP control transistor is conducting.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile