| 发明名称 |
TELEPHONE ANTISIDETONE CIRCUIT |
| 摘要 |
A transistorized wired circulator transfers power from microphone to telephone line (minimizing sidetone) and transfers power from telephone line to earphone, with microphone, telephone line, and earphone delta connected to the circulator.
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| 申请公布号 |
US3647982(A) |
申请公布日期 |
1972.03.07 |
| 申请号 |
USD3647982 |
申请日期 |
1970.08.13 |
| 申请人 |
NORTHERN ELECTRIC CO. LTD. |
发明人 |
PATRICK DAVID VAN DER PUIJE |
| 分类号 |
H04M1/58;H04M9/08;(IPC1-7):H04M1/58 |
主分类号 |
H04M1/58 |
| 代理机构 |
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代理人 |
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