发明名称 |
Communication system trunk circuit |
摘要 |
A trunk circuit for interconnecting an electronic and a step-by-step electromechanical switching exchange including a sensing circuit that is transparent to the transmission and supervisory signals. The sensing circuit consists of a pair of voltage dividers composed of at least four resistors each with the midpoint of each voltage divider connected to a voltage differential detecting means. The midpoints of the voltage dividers have substantially equal voltage levels in one state of the transmission path and have a measurable voltage differential in another state of the transmission path. Under conditions where a subscriber flash signal is not to be propagated through, the voltage dividers are arranged to have their resistance decreased, simulating an off-hook condition.
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申请公布号 |
US4049919(A) |
申请公布日期 |
1977.09.20 |
申请号 |
US19760738507 |
申请日期 |
1976.11.03 |
申请人 |
GTE AUTOMATIC ELECTRIC LABORATORIES INCORPORATED |
发明人 |
YOUNG, JOHN S. |
分类号 |
H04M7/00;(IPC1-7):H04Q3/18 |
主分类号 |
H04M7/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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