JPS5787656A - Loudspeaker transmitting system - Google Patents
Loudspeaker transmitting systemInfo
- Publication number
- JPS5787656A JPS5787656A JP16337480A JP16337480A JPS5787656A JP S5787656 A JPS5787656 A JP S5787656A JP 16337480 A JP16337480 A JP 16337480A JP 16337480 A JP16337480 A JP 16337480A JP S5787656 A JPS5787656 A JP S5787656A
- Authority
- JP
- Japan
- Prior art keywords
- loudspeaker
- microphone
- transmission
- circuit
- relay
- 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
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)
Abstract
PURPOSE:To achieve loudspeaker transmission even under noise, by automatically cutting off a microphone at the transmission of a loudspeaker telephone set. CONSTITUTION:In loudspeaker transmission, when loudspeaker switches LK1, LK2 are selected to opposite state as shown in figure, hook switches HS1, HS2 are kept at the state shown in figure, then a telephone line 1 is connected to a loudspeaker telephone set circuit 5 to achieve loudspeaker transmission. The current state at this time is identified at an identifying circuit 8 via a line current detection circuit 3 and a relay 10 is energized through an OR circuit 9, to switch a contact S and disconnect a microphone 7. When a called party responds through loudspeaker transmission, since the line current is inverted, it is identified with an identifying circuit 8 to restore the relay 10 and to re-connect the microphone 7. In this case, when a microphone disconnection switch MK1 is operated manually, the relay 10 is activated, allowing to disconnect the microphone 7 compulsively.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16337480A JPS5787656A (en) | 1980-11-21 | 1980-11-21 | Loudspeaker transmitting system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16337480A JPS5787656A (en) | 1980-11-21 | 1980-11-21 | Loudspeaker transmitting system |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5787656A true JPS5787656A (en) | 1982-06-01 |
Family
ID=15772661
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP16337480A Pending JPS5787656A (en) | 1980-11-21 | 1980-11-21 | Loudspeaker transmitting system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5787656A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6196855A (en) * | 1984-10-18 | 1986-05-15 | Rohm Co Ltd | Transmission-reception switch |
JPS61128858U (en) * | 1985-01-31 | 1986-08-12 | ||
US4790006A (en) * | 1986-03-21 | 1988-12-06 | Siemens Aktiengesellschaft | Method for electrically simulating a cradle switch and a hands free talking-loudspeaking key in a hands free talking-loudspeaking telephone station |
JPS63316551A (en) * | 1987-06-19 | 1988-12-23 | Tamura Electric Works Ltd | Hands free telephone device |
JPH01149651A (en) * | 1987-12-07 | 1989-06-12 | Fujitsu Denso Ltd | Hand-free telephone terminal equipment |
EP0330384A2 (en) * | 1988-02-18 | 1989-08-30 | Nec Corporation | Hands-free telephone |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5235907A (en) * | 1975-09-16 | 1977-03-18 | Matsushita Electric Ind Co Ltd | High sound simultaneous communication unit |
-
1980
- 1980-11-21 JP JP16337480A patent/JPS5787656A/en active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5235907A (en) * | 1975-09-16 | 1977-03-18 | Matsushita Electric Ind Co Ltd | High sound simultaneous communication unit |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6196855A (en) * | 1984-10-18 | 1986-05-15 | Rohm Co Ltd | Transmission-reception switch |
JPH0243392B2 (en) * | 1984-10-18 | 1990-09-28 | ||
JPS61128858U (en) * | 1985-01-31 | 1986-08-12 | ||
US4790006A (en) * | 1986-03-21 | 1988-12-06 | Siemens Aktiengesellschaft | Method for electrically simulating a cradle switch and a hands free talking-loudspeaking key in a hands free talking-loudspeaking telephone station |
JPS63316551A (en) * | 1987-06-19 | 1988-12-23 | Tamura Electric Works Ltd | Hands free telephone device |
JPH01149651A (en) * | 1987-12-07 | 1989-06-12 | Fujitsu Denso Ltd | Hand-free telephone terminal equipment |
EP0330384A2 (en) * | 1988-02-18 | 1989-08-30 | Nec Corporation | Hands-free telephone |
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