JPS5894257A - Voice switching circuit - Google Patents

Voice switching circuit

Info

Publication number
JPS5894257A
JPS5894257A JP19258181A JP19258181A JPS5894257A JP S5894257 A JPS5894257 A JP S5894257A JP 19258181 A JP19258181 A JP 19258181A JP 19258181 A JP19258181 A JP 19258181A JP S5894257 A JPS5894257 A JP S5894257A
Authority
JP
Japan
Prior art keywords
calling party
amplifier
circuits
losing
accordance
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
JP19258181A
Inventor
Hiroyuki Mori
Yozo Sudo
Toru Yokoyama
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP19258181A priority Critical patent/JPS5894257A/en
Publication of JPS5894257A publication Critical patent/JPS5894257A/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 get rid of a fact that the other calling party becomes entirely silent, and to prevent anxiety for setting a channel, by setting a loss value inserted into a transmitting line, in case when a calling party of a loudspeaker- telephone set is executing a call, to the extent that a room noise, etc. can be transferred to the other calling party. CONSTITUTION:On each of a transmitting line by a microphone 1 and an amplifier 2, and a receiving line by a loudspeaker 12 and an amplifier 13, variable losing circuits 5, 15, and auxiliary variable losing circuits 21, 25 are provided. A difference of the respective output levels of these circuits 5, 15 is derived by a differential amplifier 23, is compared with a reference value by the respective comparators 22, 24, in accordance with which is larger, the transmitting signal level or the receiving signal level, and in accordance with a result of its comparison, the auxiliary variable losing circuits 21, 25, etc. are controlled. In this state, in accordance with an output of the amplifier 23, a level of a high gain amplifier 8' is set, and when a calling party is not calling, a loss value inserted into the transmitting line is set to the extent that a room noise, etc. can be transferred to the other calling party, and anxiety for setting a channel is prevented.
JP19258181A 1981-11-30 1981-11-30 Voice switching circuit Pending JPS5894257A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP19258181A JPS5894257A (en) 1981-11-30 1981-11-30 Voice switching circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP19258181A JPS5894257A (en) 1981-11-30 1981-11-30 Voice switching circuit

Publications (1)

Publication Number Publication Date
JPS5894257A true JPS5894257A (en) 1983-06-04

Family

ID=16293657

Family Applications (1)

Application Number Title Priority Date Filing Date
JP19258181A Pending JPS5894257A (en) 1981-11-30 1981-11-30 Voice switching circuit

Country Status (1)

Country Link
JP (1) JPS5894257A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61161856A (en) * 1985-01-11 1986-07-22 Matsushita Electric Ind Co Ltd Loudspeaker telephone set
JPS61163469U (en) * 1985-03-26 1986-10-09
US4715062A (en) * 1985-03-22 1987-12-22 Tie/Communications, Inc. Speakerphone control circuit having low gain states and method for controlling gain of speakerphone
US4764954A (en) * 1985-02-28 1988-08-16 Kabushiki Kaisha Toshiba Automatic gain control in a loudspeaker telephone set
JPH01190163A (en) * 1988-01-26 1989-07-31 Nippon Telegr & Teleph Corp <Ntt> Security device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61161856A (en) * 1985-01-11 1986-07-22 Matsushita Electric Ind Co Ltd Loudspeaker telephone set
JPH0533579B2 (en) * 1985-01-11 1993-05-19 Matsushita Electric Ind Co Ltd
US4764954A (en) * 1985-02-28 1988-08-16 Kabushiki Kaisha Toshiba Automatic gain control in a loudspeaker telephone set
US4715062A (en) * 1985-03-22 1987-12-22 Tie/Communications, Inc. Speakerphone control circuit having low gain states and method for controlling gain of speakerphone
JPS61163469U (en) * 1985-03-26 1986-10-09
JPH0432843Y2 (en) * 1985-03-26 1992-08-06
JPH01190163A (en) * 1988-01-26 1989-07-31 Nippon Telegr & Teleph Corp <Ntt> Security device

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