发明授权
US4484034A Anti-larsen-effect arrangement in a telephone station equipped with a
loudspeaker
失效
在配有扬声器的电话台中进行防扩散效应布置
- 专利标题： Anti-larsen-effect arrangement in a telephone station equipped with a loudspeaker
- 专利标题（中）： 在配有扬声器的电话台中进行防扩散效应布置
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申请号： US500799申请日： 1983-06-07
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公开(公告)号： US4484034A公开(公告)日： 1984-11-20
- 发明人: Gilbert M. M. Ferrieu , Roger B. J. Hamel , Emmanuel Lefort , Francoise Moliere
- 申请人： Gilbert M. M. Ferrieu , Roger B. J. Hamel , Emmanuel Lefort , Francoise Moliere
- 申请人地址： FRX Savarin
- 专利权人： Telecommunications Radioelectrique et Telephoniques
- 当前专利权人： Telecommunications Radioelectrique et Telephoniques
- 当前专利权人地址： FRX Savarin
- 优先权： FRX8009411 19800425
- 主分类号： H04M1/60
- IPC分类号： H04M1/60 ; H04M9/08
摘要：
An anti-Larsen circuit for a telephone station in which the listening channel comprises an automatic listening level control circuit, suitably of the type comprising a variable attenuator circuit, a pulse-width modulator and a threshold detector which supplies compression pulses. The transmission channel comprises a circuit for rendering the transmission channel operative or inoperative and also a control circuit. Actuation takes place above a sound-level threshold S.sub.1 and a de-activation below a sound-level threshold S.sub.2 which is smaller than S.sub.1.
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