公开(公告)号：US5872842A

公开(公告)日：1999-02-16

申请号：US774228

申请日：1996-12-27

申请人： William G. Daly ,  Steven L. Caine

发明人： William G. Daly ,  Steven L. Caine

IPC分类号： H04M1/00 ,  H04M3/00 ,  H04M19/02

CPC分类号： H04M3/005 ,  H04M19/02

摘要： A communication loop using a subscriber line interface circuit (SLIC) is modified such that it can operate in unbalanced ringing environments as well as balanced ringing environments. This is accomplished by grounding the tip lead of a telephone instrument and creating an open circuit at the tip lead of the SLIC. The ring lead of the telephone instrument and the ring lead of the SLIC are electrically connected, and an AC voltage applied to the ring lead by the SLIC is increased. A power supply is connected to the SLIC and biased to provide the increased AC voltage on the SLIC ring lead while the average voltage on the SLIC tip lead is maintained substantially at ground. The result of this circuitry is a trapezoidal signal meeting the amplitude, loading and crest factor requirements of Bellcore Technical Requirement Publications TA-NWT-000909 and TR-NWT-000057.

摘要翻译： 使用用户线接口电路（SLIC）的通信环路被修改，使得其可以在不平衡振铃环境以及平衡振铃环境中操作。 这是通过将电话仪器的引线接地并在SLIC的尖端引线上产生开路来实现的。 电话乐器的环形引线和SLIC的环形引线电连接，并且由SLIC施加到环形引线的AC电压增加。 电源连接到SLIC并被偏置以在SLIC环形引线上提供增加的AC电压，而SLIC尖端引线上的平均电压基本保持在地。 该电路的结果是一个梯形信号，满足Bellcore技术要求出版物TA-NWT-000909和TR-NWT-000057的幅度，载荷和波峰因数要求。