发明名称 |
METHOD OF DETECTING LOOP CURRENT REFERENCE VALUE IN COMMUNICATION DEVICE |
摘要 |
<p>A method of and a circuit for determining current criteria in a subscriber's loop of a telephone system are described. Two constant-current sources are symmetrically connected to two wires of the loop and are controlled by an adjustable reference voltage source. Voltage signals on the voltage source are evaluated in a detecting circuit to determine the actuation of a ground button on the subscriber's set or the occurrence of a ground short-circuit. A testing device is connectable to the subscriber's loop to simulate various conditions of the subscriber's set.</p> |
申请公布号 |
JPS5880957(A) |
申请公布日期 |
1983.05.16 |
申请号 |
JP19820180102 |
申请日期 |
1982.10.15 |
申请人 |
TEKAADE FUERUTEN UNTO GIROOMU FUERUNMERUDEANRAAGEN GMBH |
发明人 |
IERUKU ROPURA;HANSU GOSHIN |
分类号 |
H04M19/00;H04M3/22;H04Q3/00 |
主分类号 |
H04M19/00 |
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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