JPS5787656A - Loudspeaker transmitting system - Google Patents

Loudspeaker transmitting system

Info

Publication number
JPS5787656A
JPS5787656A JP16337480A JP16337480A JPS5787656A JP S5787656 A JPS5787656 A JP S5787656A JP 16337480 A JP16337480 A JP 16337480A JP 16337480 A JP16337480 A JP 16337480A JP S5787656 A JPS5787656 A JP S5787656A
Authority
JP
Japan
Prior art keywords
loudspeaker
microphone
transmission
circuit
relay
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
JP16337480A
Other languages
Japanese (ja)
Inventor
Takeshi Horiuchi
Yutaka Nishino
Yoshiichi Sano
Taiji Sato
Shinichi Shibata
Makoto Yoshitoshi
Original Assignee
Nippon Telegr & Teleph Corp <Ntt>
Toshiba Corp
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 Nippon Telegr & Teleph Corp <Ntt>, Toshiba Corp filed Critical Nippon Telegr & Teleph Corp <Ntt>
Priority to JP16337480A priority Critical patent/JPS5787656A/en
Publication of JPS5787656A publication Critical patent/JPS5787656A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04MTELEPHONIC COMMUNICATION
    • H04M9/00Interconnection arrangements not involving centralised switching
    • H04M9/08Two-way loud-speaking telephone systems with means for suppressing echoes or otherwise conditioning for one or other direction of traffic

Abstract

PURPOSE:To achieve loudspeaker transmission even under noise, by automatically cutting off a microphone at the transmission of a loudspeaker telephone set. CONSTITUTION:In loudspeaker transmission, when loudspeaker switches LK1, LK2 are selected to opposite state as shown in figure, hook switches HS1, HS2 are kept at the state shown in figure, then a telephone line 1 is connected to a loudspeaker telephone set circuit 5 to achieve loudspeaker transmission. The current state at this time is identified at an identifying circuit 8 via a line current detection circuit 3 and a relay 10 is energized through an OR circuit 9, to switch a contact S and disconnect a microphone 7. When a called party responds through loudspeaker transmission, since the line current is inverted, it is identified with an identifying circuit 8 to restore the relay 10 and to re-connect the microphone 7. In this case, when a microphone disconnection switch MK1 is operated manually, the relay 10 is activated, allowing to disconnect the microphone 7 compulsively.
JP16337480A 1980-11-21 1980-11-21 Loudspeaker transmitting system Pending JPS5787656A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16337480A JPS5787656A (en) 1980-11-21 1980-11-21 Loudspeaker transmitting system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16337480A JPS5787656A (en) 1980-11-21 1980-11-21 Loudspeaker transmitting system

Publications (1)

Publication Number Publication Date
JPS5787656A true JPS5787656A (en) 1982-06-01

Family

ID=15772661

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16337480A Pending JPS5787656A (en) 1980-11-21 1980-11-21 Loudspeaker transmitting system

Country Status (1)

Country Link
JP (1) JPS5787656A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6196855A (en) * 1984-10-18 1986-05-15 Rohm Co Ltd Transmission-reception switch
JPS61128858U (en) * 1985-01-31 1986-08-12
US4790006A (en) * 1986-03-21 1988-12-06 Siemens Aktiengesellschaft Method for electrically simulating a cradle switch and a hands free talking-loudspeaking key in a hands free talking-loudspeaking telephone station
JPS63316551A (en) * 1987-06-19 1988-12-23 Tamura Electric Works Ltd Hands free telephone device
JPH01149651A (en) * 1987-12-07 1989-06-12 Fujitsu Denso Ltd Hand-free telephone terminal equipment
EP0330384A2 (en) * 1988-02-18 1989-08-30 Nec Corporation Hands-free telephone

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5235907A (en) * 1975-09-16 1977-03-18 Matsushita Electric Ind Co Ltd High sound simultaneous communication unit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5235907A (en) * 1975-09-16 1977-03-18 Matsushita Electric Ind Co Ltd High sound simultaneous communication unit

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6196855A (en) * 1984-10-18 1986-05-15 Rohm Co Ltd Transmission-reception switch
JPH0243392B2 (en) * 1984-10-18 1990-09-28
JPS61128858U (en) * 1985-01-31 1986-08-12
US4790006A (en) * 1986-03-21 1988-12-06 Siemens Aktiengesellschaft Method for electrically simulating a cradle switch and a hands free talking-loudspeaking key in a hands free talking-loudspeaking telephone station
JPS63316551A (en) * 1987-06-19 1988-12-23 Tamura Electric Works Ltd Hands free telephone device
JPH01149651A (en) * 1987-12-07 1989-06-12 Fujitsu Denso Ltd Hand-free telephone terminal equipment
EP0330384A2 (en) * 1988-02-18 1989-08-30 Nec Corporation Hands-free telephone

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