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:
Feb. 17, 1981
Filed:
Jul. 23, 1979
Kunihisa Takahashi, Kawagoe, JP;
Kozo Suzuki, Saitama, JP;
Toko, Inc., Tokyo, JP;
Abstract
A control circuit of an FM stereophonic receiver includes two sets of symmetrically arranged transistor pairs which form a DC supply regulating circuit therein and are connected to respective constant current sources. The control circuit receives an output signal from an FM detector and controls the coupling of the FM detector output to different input terminals of a switching circuit of the FM demodulator in response to a DC control signal indicative of the level of a received broadcast signal. The switching circuit receives a train of switching pulses of 38 kHz as a switching signal to derive a stereophonic or monophonic audio signal from the controllably applied FM detector output. The DC supply regulating circuit serves to maintain the DC level applied to the input terminals of the switching circuit at a constant value at all times to reduce noise which might occur in the reproduced audio signal when the receiver is switched over between the stereophonic and monophonic modes.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile