JPS5735457A - Loudspeaker telephone set system - Google Patents

Loudspeaker telephone set system

Info

Publication number
JPS5735457A
JPS5735457A JP10980280A JP10980280A JPS5735457A JP S5735457 A JPS5735457 A JP S5735457A JP 10980280 A JP10980280 A JP 10980280A JP 10980280 A JP10980280 A JP 10980280A JP S5735457 A JPS5735457 A JP S5735457A
Authority
JP
Japan
Prior art keywords
control signal
amplifier
transmission
reception
negative
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10980280A
Other languages
Japanese (ja)
Inventor
Tokiyoshi Mitani
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oki Electric Industry Co Ltd
Original Assignee
Oki Electric Industry Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oki Electric Industry Co Ltd filed Critical Oki Electric Industry Co Ltd
Priority to JP10980280A priority Critical patent/JPS5735457A/en
Publication of JPS5735457A publication Critical patent/JPS5735457A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Abstract

PURPOSE:To prevent excessive loudspeaking by converting and negative-feeding back a transmission signal into a control signal and to suppress a slight tone simply with a variable gain adjuster. CONSTITUTION:A transmission signal outputted from an amplifier 19 is transmitted to a line 5 and given to a control signal generator 20, a transmission signal is converted into a control signal with a control signal generator 20 and negative-fed back to a variable gain adjusting circuit 18 to control the output level of the amplifier 19 to a constant value. On the other hand, a transmission signal leaked to the reception system with the coupling 12 between the transmission and reception systems flows to the reception system as the reception signaln and amplified at an amplifier 21, this output is given to the control signal generator 20, this is converted into a control signal and negative-fed back to the variable gain adjusting circuit 18. This controls the output level of the amplifier 19 accordng to the amount of coupling between the transmission and reception systems via a hybrid circuit 4.
JP10980280A 1980-08-12 1980-08-12 Loudspeaker telephone set system Pending JPS5735457A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10980280A JPS5735457A (en) 1980-08-12 1980-08-12 Loudspeaker telephone set system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10980280A JPS5735457A (en) 1980-08-12 1980-08-12 Loudspeaker telephone set system

Publications (1)

Publication Number Publication Date
JPS5735457A true JPS5735457A (en) 1982-02-26

Family

ID=14519579

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10980280A Pending JPS5735457A (en) 1980-08-12 1980-08-12 Loudspeaker telephone set system

Country Status (1)

Country Link
JP (1) JPS5735457A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6057847A (en) * 1983-09-09 1985-04-03 Canon Inc Electrophotographic sensitive body
JPS616969A (en) * 1984-06-21 1986-01-13 Fujitsu Ltd System for preventing head of speech intermission
JPS63221350A (en) * 1987-01-30 1988-09-14 ゼロックス　コーポレーション Non-moisture sensitive/photosensitive image forming member
US4912000A (en) * 1988-02-05 1990-03-27 Japan Atomic Energy Research Institute Electrophotographic photoreceptor
WO1999007134A1 (en) * 1997-07-28 1999-02-11 Siemens Aktiengesellschaft Hand free system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6057847A (en) * 1983-09-09 1985-04-03 Canon Inc Electrophotographic sensitive body
JPH0155449B2 (en) * 1983-09-09 1989-11-24 Canon Kk
JPS616969A (en) * 1984-06-21 1986-01-13 Fujitsu Ltd System for preventing head of speech intermission
JPS63221350A (en) * 1987-01-30 1988-09-14 ゼロックス　コーポレーション Non-moisture sensitive/photosensitive image forming member
US4912000A (en) * 1988-02-05 1990-03-27 Japan Atomic Energy Research Institute Electrophotographic photoreceptor
WO1999007134A1 (en) * 1997-07-28 1999-02-11 Siemens Aktiengesellschaft Hand free system

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