发明名称 |
UNA INSTALACION DE TELECOMUNICACION PARTICULARMENTE PARA COMUNICACIONES TELEFONICAS. |
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 |
ES516099(D0) |
申请公布日期 |
1983.11.01 |
申请号 |
ES19990005160 |
申请日期 |
1982.09.30 |
申请人 |
TE KA DE FELTEN & GUILLEAUME FERNMELDEANLAGEN GMBH |
发明人 |
|
分类号 |
H04M19/00;H04M3/22;H04Q3/00;(IPC1-7):04Q3/24;04M3/06;04Q1/20;04M19/00 |
主分类号 |
H04M19/00 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|