ELEKTRONISK KRETSANORDNING I EN TELEFONVEXEL FOR STROMMATNING AV TELEFONIKRETSAR,申请号SE19780007783-传众专利搜索

ELEKTRONISK KRETSANORDNING I EN TELEFONVEXEL FOR STROMMATNING AV TELEFONIKRETSAR

申请公布号：SE7807783(L)

申请号：SE19780007783

申请日期：1978.07.13

申请公布日期：1980.01.14

申请人：

ELLEMTEL UTVECKLINGS AB

发明人：HAMMARBERG L

分类号：H04M19/00;(IPC1-7):H04M19/00

主分类号：H04M19/00

摘要：An electric circuit arrangement which is part of a telephone exchange and is connected to a power source for supplying current to the telephone sets connected to the exchange. The circuit arrangement contains two differential amplifiers OP1, OP2, one of which OP1 senses the feed current I to the line by detecting the voltage drop across a resistance r, directly connected to the line. The second differential amplifier OP2 senses any voltage changes across the line Le and sends a control quantity to an emitter sensor T connected in series between the power source so that the line current changes in dependence on the voltage change across the line. The circuit thus acts as a simulated impedance for the transverse line signals. <IMAGE>