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. 13, 1983
Filed:
Nov. 20, 1981
Minoru Ogita, Hamamatsu, JP;
Nippon Gakki Seizo Kabushiki Kaisha, Hamamatsu, JP;
Abstract
An FM stereo demodulation circuit comprises a resistor voltage dividing network having a plurality of outputs; a first switch circuit having a plurality of analog switches which respectively couple the outputs of the voltage dividing network to a first output terminal; a second switch circuit having a plurality of analog switches which respectively couple the outputs of the voltage dividing network to a second output terminal; and a switch control circuit which sequentially enables the analog switches of the first and second switch circuits over one cycle period of a subscarrier signal in response to a pilot signal in an FM stereo composite signal. The circuits produce a staircase-wave multiplying signal having a waveshape which depends on the setting of the resistance values of resistors of the voltage dividing network. The FM stereo composite signal having the pilot signal therein or the pilot signal removed therefrom prior to demodulation is applied to the voltage dividing network so that the FM stereo composite signal is multiplied by the multiplying signal to accomplish the FM stereo demodulation.