IT1116453B - IMPROVEMENT IN INTERCOMMUNICATIONS SYSTEMS - Google Patents
IMPROVEMENT IN INTERCOMMUNICATIONS SYSTEMSInfo
- Publication number
- IT1116453B IT1116453B IT48751/79A IT4875179A IT1116453B IT 1116453 B IT1116453 B IT 1116453B IT 48751/79 A IT48751/79 A IT 48751/79A IT 4875179 A IT4875179 A IT 4875179A IT 1116453 B IT1116453 B IT 1116453B
- Authority
- IT
- Italy
- Prior art keywords
- intercommunications
- improvement
- systems
- intercommunications systems
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/40—Circuits
- H04B1/44—Transmit/receive switching
- H04B1/46—Transmit/receive switching by voice-frequency signals; by pilot signals
-
- 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
- H04M9/10—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic with switching of direction of transmission by voice frequency
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interconnected Communication Systems, Intercoms, And Interphones (AREA)
- Mobile Radio Communication Systems (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB7831781A GB2027566A (en) | 1978-08-01 | 1978-08-01 | Automatic intercom |
Publications (2)
Publication Number | Publication Date |
---|---|
IT7948751A0 IT7948751A0 (en) | 1979-04-17 |
IT1116453B true IT1116453B (en) | 1986-02-10 |
Family
ID=10498781
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
IT48751/79A IT1116453B (en) | 1978-08-01 | 1979-04-17 | IMPROVEMENT IN INTERCOMMUNICATIONS SYSTEMS |
Country Status (4)
Country | Link |
---|---|
DE (1) | DE2850874A1 (en) |
FR (1) | FR2432800A1 (en) |
GB (1) | GB2027566A (en) |
IT (1) | IT1116453B (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2159375A (en) * | 1984-05-19 | 1985-11-27 | Advance Electronic Prod | Interrupt on priority communication systems |
US5239687A (en) * | 1991-05-06 | 1993-08-24 | Chen Shih Chung | Wireless intercom having a transceiver in which a bias current for the condenser microphone and the driving current for the speaker are used to charge a battery during transmission and reception, respectively |
-
1978
- 1978-08-01 GB GB7831781A patent/GB2027566A/en active Pending
- 1978-11-24 DE DE19782850874 patent/DE2850874A1/en active Pending
-
1979
- 1979-04-17 IT IT48751/79A patent/IT1116453B/en active
- 1979-05-07 FR FR7911492A patent/FR2432800A1/en not_active Withdrawn
Also Published As
Publication number | Publication date |
---|---|
FR2432800A1 (en) | 1980-02-29 |
DE2850874A1 (en) | 1980-02-14 |
IT7948751A0 (en) | 1979-04-17 |
GB2027566A (en) | 1980-02-20 |
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