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
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