DE3851797D1 - Laut-Fernsprechgerät mit einer variablen Verstärkungsschaltung. - Google Patents

Laut-Fernsprechgerät mit einer variablen Verstärkungsschaltung.

Info

Publication number
DE3851797D1
DE3851797D1 DE3851797T DE3851797T DE3851797D1 DE 3851797 D1 DE3851797 D1 DE 3851797D1 DE 3851797 T DE3851797 T DE 3851797T DE 3851797 T DE3851797 T DE 3851797T DE 3851797 D1 DE3851797 D1 DE 3851797D1
Authority
DE
Germany
Prior art keywords
variable gain
gain circuit
loud
telephone
loud telephone
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.)
Expired - Fee Related
Application number
DE3851797T
Other languages
English (en)
Other versions
DE3851797T2 (de
Inventor
Keiko C O Nec Corporat Shimada
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.)
NEC Corp
Original Assignee
NEC 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 NEC Corp filed Critical NEC Corp
Application granted granted Critical
Publication of DE3851797D1 publication Critical patent/DE3851797D1/de
Publication of DE3851797T2 publication Critical patent/DE3851797T2/de
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
  • Amplifiers (AREA)
DE3851797T 1987-07-06 1988-07-06 Laut-Fernsprechgerät mit einer variablen Verstärkungsschaltung. Expired - Fee Related DE3851797T2 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62169272A JPS6412649A (en) 1987-07-06 1987-07-06 Variable gain circuit for loudspeaker telephone set

Publications (2)

Publication Number Publication Date
DE3851797D1 true DE3851797D1 (de) 1994-11-17
DE3851797T2 DE3851797T2 (de) 1995-05-04

Family

ID=15883432

Family Applications (1)

Application Number Title Priority Date Filing Date
DE3851797T Expired - Fee Related DE3851797T2 (de) 1987-07-06 1988-07-06 Laut-Fernsprechgerät mit einer variablen Verstärkungsschaltung.

Country Status (7)

Country Link
US (1) US4899380A (de)
EP (1) EP0298719B1 (de)
JP (1) JPS6412649A (de)
KR (1) KR910004058B1 (de)
AU (1) AU608484B2 (de)
CA (1) CA1294081C (de)
DE (1) DE3851797T2 (de)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5170430A (en) * 1991-01-04 1992-12-08 Schuh Peter O Voice-switched handset receive amplifier
US5650181A (en) * 1993-06-17 1997-07-22 Kotaki; Daizo Injection molding die for producing plastic filter
US5555300A (en) * 1994-03-07 1996-09-10 Gutzmer; Howard A. Telephone handset microphone level adjustment
US5912964A (en) * 1996-03-27 1999-06-15 Hello Direct, Inc. Adaptive telephone handset interface
US5892823A (en) 1996-03-27 1999-04-06 Hello Direct, Inc. Smart interface technology
US6343126B1 (en) 1996-03-27 2002-01-29 Hello Direct, Inc. Method and apparatus for interfacing analog telephone apparatus to a digital, analog or hybrid telephone switching system
US7433462B2 (en) * 2002-10-31 2008-10-07 Plantronics, Inc Techniques for improving telephone audio quality
US20050238757A1 (en) * 2004-04-23 2005-10-27 Niewels Joachim J Method and apparatus for assisting ejection from an injection molding machine using active material elements
US7072735B2 (en) * 2004-04-23 2006-07-04 Husky Injection Molding Systems Ltd. Control system for utilizing active material elements in a molding system

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3725585A (en) * 1972-03-21 1973-04-03 Itt Loudspeaking telephone station circuit
US4025728A (en) * 1976-01-29 1977-05-24 Sava Jacobson Speaker telephone
JPS5392608A (en) * 1977-01-25 1978-08-14 Nippon Telegr & Teleph Corp <Ntt> Voice switch circuit
CA1134522A (en) * 1980-04-30 1982-10-26 James L.E. Thompson Voice switch for hands free communication apparatus
DE3218501A1 (de) * 1981-12-05 1983-11-17 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Schaltungsanordnung zur gegensinnigen verstaerkungssteuerung
DE3248501A1 (de) * 1982-12-29 1984-07-05 Peter W. D. van der 4926 Dörentrup Heijden Kuehlvorrichtung fuer vakuum-destillierapparate und verfahren zur durchfuehrung der destillationskuehlung
JPS59147561A (ja) * 1983-02-10 1984-08-23 Fujitsu Ltd 拡声電話機回路
JPS60230753A (ja) * 1984-04-28 1985-11-16 Fujitsu Ltd 拡声電話装置
AU4322985A (en) * 1984-06-22 1986-01-02 Stc Plc Telephone subscriber instrument
JPS6188643A (ja) * 1984-10-05 1986-05-06 Tamura Electric Works Ltd ハンドフリ−回路
US4629829A (en) * 1984-12-14 1986-12-16 Motorola, Inc. Full duplex speakerphone for radio and landline telephones
JPS61161856A (ja) * 1985-01-11 1986-07-22 Matsushita Electric Ind Co Ltd 拡声電話装置
FR2582885B1 (fr) * 1985-05-31 1988-03-18 Zurcher Frederic Circuit de transmission a double sens muni de moyens de reglage automatique du gain selon le sens de transmission.

Also Published As

Publication number Publication date
DE3851797T2 (de) 1995-05-04
JPS6412649A (en) 1989-01-17
EP0298719A2 (de) 1989-01-11
CA1294081C (en) 1992-01-07
EP0298719A3 (en) 1989-06-07
US4899380A (en) 1990-02-06
KR890003193A (ko) 1989-04-13
AU608484B2 (en) 1991-03-28
EP0298719B1 (de) 1994-10-12
KR910004058B1 (ko) 1991-06-22
AU1873588A (en) 1989-01-12

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Legal Events

Date Code Title Description
8364 No opposition during term of opposition
8339 Ceased/non-payment of the annual fee