公开(公告)号：US4356355A

公开(公告)日：1982-10-26

申请号：US207118

申请日：1980-11-17

申请人： Gilbert M. M. Ferrieu ,  Etienne J. R. Osmond ,  Yves J. F. Hetet

发明人： Gilbert M. M. Ferrieu ,  Etienne J. R. Osmond ,  Yves J. F. Hetet

IPC分类号： H04M3/02 ,  H04M19/02

CPC分类号： H04M19/026

摘要： Apparatus for detecting the closure of a subscriber's telephone line in the presence of an alternating ringing voltage superimposed on a direct voltage comprises circuitry for producing a unidirectional current from the combined alternating and direct voltages. When the line is open no direct current will flow and hence the peak value of successive half cycles will be equal whereas when the loop is closed and direct current flows the peak values of successive peaks will be different. A capacitor (26) is charged by a voltage (U.sub.1), which is proportional to the combined voltage, through a transistor (24), provided that the voltage (U.sub.1) is greater than the voltage across the capacitor, and discharged through a resistor (27). The time constant of the discharge circuit is selected so that when the line is looped the smaller peak is lower than the voltage to which the capacitor is discharged and hence charging current flows into capacitor (26) on alternate peaks of the voltage (U.sub.1) only. The intervals between pulses of charging current are determined by a comparator (33) which provides an output (S) which indicates whether the subscriber's line is closed.

摘要翻译： 用于在存在叠加在直流电压上的交替振铃电压的情况下检测用户电话线路的闭合的装置包括用于从组合的交流和直流电压产生单向电流的电路。 当线路打开时，不会有直流电流流动，因此连续半周期的峰值将相等，而当环路闭合并且直流电流流动时，连续峰值的峰值将不同。 只要电压（U1）大于电容器两端的电压，电容器（26）通过晶体管（24）与与组合电压成比例的电压（U1）充电，并通过电阻器 （27）。 选择放电电路的时间常数，使得当线路环路时，较小的峰值低于电容器放电的电压，因此充电电流仅在电压（U1）的交替峰值上流入电容器（26） 。 充电电流的脉冲之间的间隔由提供输出（S）的比较器（33）确定，该输出指示用户的线路是否闭合。

公开(公告)号：US4414434A

公开(公告)日：1983-11-08

申请号：US249283

申请日：1981-03-30

申请人： Gilbert M. M. Ferrieu ,  Etienne J. R. Osmond ,  Yves J. F. Hetet

发明人： Gilbert M. M. Ferrieu ,  Etienne J. R. Osmond ,  Yves J. F. Hetet

IPC分类号： H04M19/00

CPC分类号： H04M19/005

摘要： In this subscriber line interface circuit which comprises a pair of amplifiers whose outputs are connected to the subscriber's line, the input terminals of these amplifiers receive by means of negative feedback voltages having opposite phases depending on the transversal current I produced by the line interface circuit and independent of the longitudinal currents I accidentally produced on the subscriber's line. The two load impedances, which are connected between the supply terminals of the amplifiers and the terminals of a d.c. voltage supply source are controlled by means of their control terminals by voltages which have the same characteristics as the voltages applied to the input terminals of the amplifiers but which in addition have been shifted with a certain shift voltage V.sub.z. Consequently, the amplifiers of the line interface circuit operate completely independent of the longitudinal currents.

摘要翻译： 在该用户线接口电路中，其包括一对放大器，其输出连接到用户线，这些放大器的输入端通过负反馈电压接收，该反馈电压具有取决于线路接口电路产生的横向电流I的相反相位， 独立于我在用户线上意外产生的纵向电流。 两个负载阻抗连接在放大器的电源端和直流电源端子之间。 电压源由其控制端子通过与施加到放大器的输入端子的电压具有相同特性的电压来控制，而另外已经以一定的移位电压Vz移位。 因此，线路接口电路的放大器完全独立于纵向电流。