发明名称 |
Loop, dial pulse and ring trip detection circuit |
摘要 |
A circuit which detects the presence and absence of a telephone subscriber loop, before and after ringing current is applied to the loop. Coils functioning as magnetic field generating devices and a Hall effect device are used to perform the detection function.
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申请公布号 |
US4166928(A) |
申请公布日期 |
1979.09.04 |
申请号 |
US19770865761 |
申请日期 |
1977.12.29 |
申请人 |
GTE AUTOMATIC ELECTRIC LABORATORIES INC |
发明人 |
SABON, ROBERT J |
分类号 |
H04M3/22;H04M19/02;(IPC1-7):H04B3/46;H04M3/02 |
主分类号 |
H04M3/22 |
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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