发明授权
- 专利标题: Call detection control apparatus
- 专利标题(中): 呼叫检测控制装置
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申请号: US71777申请日: 1993-06-04
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公开(公告)号: US5416832A公开(公告)日: 1995-05-16
- 发明人: Toshio Nitta , Toshikatsu Kobayashi , Takeshi Sasaki , Tooru Ikeda
- 申请人: Toshio Nitta , Toshikatsu Kobayashi , Takeshi Sasaki , Tooru Ikeda
- 申请人地址: JPX Tokyo
- 专利权人: NEC Corporation
- 当前专利权人: NEC Corporation
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX4-145105 19920605; JPX4-223705 19920824
- 主分类号: H04M3/00
- IPC分类号: H04M3/00 ; H04M3/22
摘要:
A call detection control apparatus includes individual call detecting circuits, a common call detecting circuit, switching circuits, and a power supply circuit. The individual call detecting circuits individually detect call signals, which originate from telephone subscriber lines. The common call detecting circuit commonly detects call signals, which originate from the respective telephone subscriber lines. The switching circuits switch the respective telephone subscriber lines from the common call detecting circuit to the respective individual call detecting circuit when the common call detecting circuit detects an call signal from one of the respective telephone subscriber lines. The power supply circuit supplies operating power to each of the individual call detecting circuits upon interlocking with an operation of a corresponding one of the switching circuits.
公开/授权文献
- US6012648A Apparatus and method for locking a spray boom 公开/授权日:2000-01-11
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