Method and an arrangement for generating a ringing

专利名称：Method and an arrangement for generating

a ringing signal

发明人：Torbjorn I. Randahl申请号：US08/375687申请日：19950120公开号：US05553132A公开日：19960903

摘要：To generate a ringing signal by means of a subscriber line interface circuithaving two final stages, each for supplying an individual subscriber line wire, one of thesubscriber line wires is connected to one of the input terminals of an operational

amplifier, the other input terminal of which being connected to the interconnecting pointbetween two series connected resistors having the same resistance. The output terminalof the operational amplifier is connected, via a first resistor, to a current input terminal ofthe subscriber line interface circuit for generating a first current. A signal generator, via asecond resistor, is also connected to said current input terminal for generating a secondcurrent. The final stages of the subscriber line interface circuit are supplied with currentfrom current input terminal to drive the final stages to generate the ringing signal.

申请人：TELEFONAKTIEBOLAGET LM ERICSSON

代理机构：Burns, Doane, Swecker & Mathis, LP.

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