JPS5742242A - Two-wire type bidirectional amplifier system - Google Patents
Two-wire type bidirectional amplifier systemInfo
- Publication number
- JPS5742242A JPS5742242A JP11795580A JP11795580A JPS5742242A JP S5742242 A JPS5742242 A JP S5742242A JP 11795580 A JP11795580 A JP 11795580A JP 11795580 A JP11795580 A JP 11795580A JP S5742242 A JPS5742242 A JP S5742242A
- Authority
- JP
- Japan
- Prior art keywords
- amount
- circuit
- erasion
- echo
- loss
- 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.)
- Granted
Links
Landscapes
- Amplifiers (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
PURPOSE:To prevent the deterioration in quality of call due to level contrast, by reducing the amount of loss of one variable amplifying circuit by the amount corresponding to echo erasion, through the output of a detection circuit estimating the amount of erasion of echo. CONSTITUTION:When a signal comes from two-wire side at the E side, an echo erasing circuit 12 is operated to cancel the amount of echo produced at two/four- wire conversion point 4, the amount of echo erasion is estimated at an echo erasing amount detection circuit 20 and control is made so that the amount of loss of a variable gain amplifying circuit 6' at the W side can be reduced within the amount of erasion. When a call signal comes also to the W side from this state, the output of the circuit 20 is held. Next, when call is by the W side only, the circuit 6' at the W side becomes the gain and the circuit 5' becomes the loss and the loss of the circuit 5' can be reduced by the range of the amount of erasion. Thus, the loss inserted to the opposing side can be reduced to the same gain as that toward call with the amount of erasion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11795580A JPS5742242A (en) | 1980-08-27 | 1980-08-27 | Two-wire type bidirectional amplifier system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11795580A JPS5742242A (en) | 1980-08-27 | 1980-08-27 | Two-wire type bidirectional amplifier system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5742242A true JPS5742242A (en) | 1982-03-09 |
| JPS6223936B2 JPS6223936B2 (en) | 1987-05-26 |
Family
ID=14724371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11795580A Granted JPS5742242A (en) | 1980-08-27 | 1980-08-27 | Two-wire type bidirectional amplifier system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5742242A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57129542A (en) * | 1981-02-04 | 1982-08-11 | Nippon Telegr & Teleph Corp <Ntt> | Two-way repeater |
| JPS59205833A (en) * | 1983-05-09 | 1984-11-21 | Nec Corp | Device for suppressing stray signal |
| JPS6070830A (en) * | 1983-09-28 | 1985-04-22 | Hitachi Ltd | Singing control system |
| JPS61194958A (en) * | 1985-02-22 | 1986-08-29 | Nippon Telegr & Teleph Corp <Ntt> | Echo canceller type loud speaker telephone circuit |
| JPS62283722A (en) * | 1985-06-13 | 1987-12-09 | ジ−メンス・アクチエンゲゼルシヤフト | Transmission circuit apparatus with amplifier |
| US4782525A (en) * | 1985-11-25 | 1988-11-01 | Northern Telecom Limited | Echo cancellation in two-wire transmission path repeaters |
| US4942314A (en) * | 1987-09-18 | 1990-07-17 | Sanyo Electric Co., Ltd. | Peak holding circuit for a color television receiver |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5742241A (en) * | 1980-08-27 | 1982-03-09 | Nec Corp | Echo erasion type two-wire bidirectional amplifier |
-
1980
- 1980-08-27 JP JP11795580A patent/JPS5742242A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5742241A (en) * | 1980-08-27 | 1982-03-09 | Nec Corp | Echo erasion type two-wire bidirectional amplifier |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57129542A (en) * | 1981-02-04 | 1982-08-11 | Nippon Telegr & Teleph Corp <Ntt> | Two-way repeater |
| JPS59205833A (en) * | 1983-05-09 | 1984-11-21 | Nec Corp | Device for suppressing stray signal |
| JPS6070830A (en) * | 1983-09-28 | 1985-04-22 | Hitachi Ltd | Singing control system |
| JPS61194958A (en) * | 1985-02-22 | 1986-08-29 | Nippon Telegr & Teleph Corp <Ntt> | Echo canceller type loud speaker telephone circuit |
| JPS62283722A (en) * | 1985-06-13 | 1987-12-09 | ジ−メンス・アクチエンゲゼルシヤフト | Transmission circuit apparatus with amplifier |
| US4782525A (en) * | 1985-11-25 | 1988-11-01 | Northern Telecom Limited | Echo cancellation in two-wire transmission path repeaters |
| US4942314A (en) * | 1987-09-18 | 1990-07-17 | Sanyo Electric Co., Ltd. | Peak holding circuit for a color television receiver |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6223936B2 (en) | 1987-05-26 |
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