发明名称 |
System and method for eliminating bell tap on analog telephones |
摘要 |
A system and method for modifying a composite Ring AC/Message Waiting (RAC/MW) signal to prevent bell tap on analog telephones. The composite RAC/MW signal comprises AC signals and DC signal alternately spaced in time. At a zero crossover point the composite RAC/MW signal is ramped from a given bias voltage level to a desired Message Waiting voltage level at a slope sufficient to prevent bell tap. Near the end of the Message Waiting portion of the composite signal the composite signal is ramped to the bias voltage level at a slope sufficient to prevent bell tap.
|
申请公布号 |
US5602911(A) |
申请公布日期 |
1997.02.11 |
申请号 |
US19930059486 |
申请日期 |
1993.05.10 |
申请人 |
SIEMENS BUSINESS COMMUNICATION SYSTEMS, INC. |
发明人 |
OST, SR., EDWIN L. |
分类号 |
H04M1/82;H04M3/537;H04M19/02;(IPC1-7):H04M1/00;H04M3/00;H04M9/00 |
主分类号 |
H04M1/82 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|