发明名称 |
Integrated ring sensor with fault detection |
摘要 |
A power cross circuit detects a ring trip condition in order to switch a pair of switch relays to a protection circuit and to appropriate line driver circuitry to enable a talking condition for a telephone. The power cross circuit detects a rise in a DC current across a feed resistor connected to a ring bus and a ring line. The power cross circuit determines a difference in current passing across a first and second sense amplifier connected to respective ends of the feed resistor. The current difference is then converted to a voltage difference, and utilized by the power cross circuit to output a power cross condition when the current difference exceeds a predetermined value.
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申请公布号 |
US5809109(A) |
申请公布日期 |
1998.09.15 |
申请号 |
US19950457668 |
申请日期 |
1995.06.01 |
申请人 |
ADVANCED MICRO DEVICES, INC. |
发明人 |
MOYAL, MICHAEL;SCHOPFER, WALTER S. |
分类号 |
H04M1/74;H04M3/02;H04M3/18;H04M3/30;(IPC1-7):H04M1/24 |
主分类号 |
H04M1/74 |
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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