| 发明名称 |
OPERATOR*S COMMUNICATION SYSTEM |
| 摘要 |
PURPOSE:To provide a system capable of making fixed characteristic impedance by composing an operator intervening circuit by use of amplifiers and hybrid circuits in a four-line telephone exchange network. |
| 申请公布号 |
JPS522309(A) |
申请公布日期 |
1977.01.10 |
| 申请号 |
JP19750078720 |
申请日期 |
1975.06.24 |
| 申请人 |
NIPPON DENKI KK;NIPPON DENSHIN DENWA KOSHA |
发明人 |
ABE SHIYOUICHI;KANEDA YOSHIHITO |
| 分类号 |
H04M3/56;H04B3/03;H04M3/60;H04M5/00;H04M9/02 |
主分类号 |
H04M3/56 |
| 代理机构 |
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代理人 |
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| 主权项 |
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| 地址 |
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