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. 28, 1980
Filed:
Dec. 22, 1978
Kazuyoshi Fujiyoshi, Fukuoka, JP;
Kyoji Murakami, Fukuoka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An antisidetalk signal control circuit for preventing transmission of signals from a first source connected with a first input circuit to an output circuit while allowing the transmission of signals from a second source connected with a second input circuit to the output circuit. The signal control circuit comprises a first switching circuit having an input coupled to the first input circuit, a second switching circuit having an input coupled to the first output circuit through a phase inverter and a third switching circuit having an input coupled to the outputs of the first and second switching circuits. An oscillator drives the first switching circuit with signals having a given phase and the second and third switching circuits with signals of opposite phase. A low-pass filter couples the junction of the first and second switching circuits to the second input circuit and a feedback circuit couples the second input circuit to the junction of the first and second switching circuits. The reduction in sidetalk is not affected by variations in the impedances of the first and second signal sources.