GB620695A - Improvements in or relating to amplifying devices for use with telephone sets - Google Patents

Improvements in or relating to amplifying devices for use with telephone sets

Info

Publication number
GB620695A
GB620695A GB1836746A GB1836746A GB620695A GB 620695 A GB620695 A GB 620695A GB 1836746 A GB1836746 A GB 1836746A GB 1836746 A GB1836746 A GB 1836746A GB 620695 A GB620695 A GB 620695A
Authority
GB
United Kingdom
Prior art keywords
loud
speaker
microphone
amplifier
hand
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
Application number
GB1836746A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to GB1836746A priority Critical patent/GB620695A/en
Publication of GB620695A publication Critical patent/GB620695A/en
Expired 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

620,695. Substation apparatus. PEERS, J. H. R. June 19, 1946, No. 18367. [Class 40 (iv)] In a loud-speaking extension arrangement in which the receiver of an ordinary hand-set is acoustically coupled to a microphone connected through an amplifier to the loud-speaker, and in which the transmitter of the hand-set is acoustically operated by a small loud-speaker fed through an amplifier from an external microphone, a support for the hand-set comprises a casing lined with sound-absorbing material and having cavities Q, K containing a microphone A and a loud-speaker B, an air space S being provided to form an acoustic barrier therebetween. The hand-set when in position engages rubber collars at the entrances to the cavities and operates a switch T. Microphone A feeds the amplifier D through a volume control C, the amplified signal being reproduced by loud-speaker E, while an amplifier H coupled to the loud-speaker B is fed by microphone F through volume control G. The switch T controls the power supply to the amplifiers which may receive reduced heating current during standby periods, and may also control signal lamps to indicate the standby and operating condition of the amplifiers.
GB1836746A 1946-06-19 1946-06-19 Improvements in or relating to amplifying devices for use with telephone sets Expired GB620695A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1836746A GB620695A (en) 1946-06-19 1946-06-19 Improvements in or relating to amplifying devices for use with telephone sets

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1836746A GB620695A (en) 1946-06-19 1946-06-19 Improvements in or relating to amplifying devices for use with telephone sets

Publications (1)

Publication Number Publication Date
GB620695A true GB620695A (en) 1949-03-29

Family

ID=10111249

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1836746A Expired GB620695A (en) 1946-06-19 1946-06-19 Improvements in or relating to amplifying devices for use with telephone sets

Country Status (1)

Country Link
GB (1) GB620695A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3360071A (en) * 1965-08-02 1967-12-26 Chromalloy Corp Acoustical coupler
FR2603440A1 (en) * 1986-09-01 1988-03-04 Eppendahl Pierre HANDS-FREE TELEPHONE CONFIGURATION FOR TELECONFERENCES
US5063590A (en) * 1989-06-29 1991-11-05 Ricoh Company, Ltd. Acoustic coupler and data transmission apparatus using the same
GB2261571A (en) * 1991-11-12 1993-05-19 Yang Chao Ming Handsfree mobile telephone rack

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3360071A (en) * 1965-08-02 1967-12-26 Chromalloy Corp Acoustical coupler
FR2603440A1 (en) * 1986-09-01 1988-03-04 Eppendahl Pierre HANDS-FREE TELEPHONE CONFIGURATION FOR TELECONFERENCES
WO1988001821A1 (en) * 1986-09-01 1988-03-10 Pierre Charles Eppendahl Telephone configuration of the hands-free type for teleconferences
US5063590A (en) * 1989-06-29 1991-11-05 Ricoh Company, Ltd. Acoustic coupler and data transmission apparatus using the same
GB2261571A (en) * 1991-11-12 1993-05-19 Yang Chao Ming Handsfree mobile telephone rack

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