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 setsInfo
- 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
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.
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)
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 |
-
1946
- 1946-06-19 GB GB1836746A patent/GB620695A/en not_active Expired
Cited By (5)
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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