| Original document(11 pages) 中文版 |
In the present invention, are adopted gated switch, code counter, programmed received-code counter, controller and first-digit discriminator, busy tone and strong tone discriminator and other circuits. The said controller can effectively prevent that the subscriber directly dials a long-distance telephone by using the programmed exchange of muncipal office or directly calls up long-distanc telephone by using long-distance exchange. It can also prevent the subscriber from calling up a long-distance telephone by eliminating the busy tone and strong tone of municipal office. |
Application Number
申请号 |
90100109 |
Application Date
申请日 |
1990.01.05 |
| Title 名称 |
Controller of outgoing toll telephone |
Publication Number
公开号 |
1046426 |
Publication Date
公开日 |
1990.10.24 |
| Approval Pub. Date |
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Granted Pub. Date |
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| International Classification 分类号 |
H04M3/38 |
Applicant(s) Name
申请人 |
Communication Battalion, Unit No. 38614, CPLA |
| Address 地址 |
116021 |
| Inventor(s) Name 发明人 |
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| Attorney & Agent 代理人 |
ZHU XIANGAO |
| More information 更 多 信 息 |
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