公开(公告)号：EP0334220B1

公开(公告)日：1994-11-30

申请号：EP89104766.4

申请日：1989-03-17

申请人： FUJITSU LIMITED

发明人： Takato, Kenji ,  Tojo, Toshiro ,  Kinoshita, Kazumi ,  Yamamoto, Yuzo City Kopu Motosumiyoshi 301

IPC分类号： H03F1/08 ,  H03F3/45

CPC分类号： H03F3/45085 ,  H03F1/083 ,  H03F2200/516 ,  H03F2203/45496 ,  H03F2203/45664 ,  H03F2203/45708

公开(公告)号：EP0412560B1

公开(公告)日：1994-08-17

申请号：EP90115401.3

申请日：1990-08-10

申请人： FUJITSU LIMITED

发明人： Takato, Kenji ,  Tojo, Toshiro ,  Yamamoto, Yuzo, 301, City Coop Motosumiyoshi

IPC分类号： H04M19/00 ,  H04B3/03

CPC分类号： H04M19/005

公开(公告)号：EP0295683B1

公开(公告)日：1993-09-22

申请号：EP88109654.9

申请日：1988-06-16

申请人： FUJITSU LIMITED

发明人： Tojo, Toshiro ,  Takato, Kenji ,  Kinoshita, Kazumi ,  Yamamoto, Yuzo

IPC分类号： H04M3/18 ,  H04M19/00 ,  H02H9/02

CPC分类号： H04M3/18 ,  H02H9/025 ,  H04M19/001

公开(公告)号：EP0212632B1

公开(公告)日：1992-11-25

申请号：EP86111530.1

申请日：1986-08-20

申请人： FUJITSU LIMITED

发明人： Takato, Kenji ,  Tojo, Toshiro ,  Iketani, Yozo ,  Ayano, Mitsutoshi ,  Shibuya, Kiyoshi

IPC分类号： H04M19/00

CPC分类号： H04M19/005

公开(公告)号：EP0412560A3

公开(公告)日：1991-10-09

申请号：EP90115401.3

申请日：1990-08-10

申请人： FUJITSU LIMITED

发明人： Takato, Kenji ,  Tojo, Toshiro ,  Yamamoto, Yuzo, 301, City Coop Motosumiyoshi

IPC分类号： H04M19/00 ,  H04B3/03

CPC分类号： H04M19/005

摘要： A hybrid circuit which converts receiving side four-wire signals from a switching network into two-­wire signals, supplies the same through line B and line A to a telephone terminal equipment, and converts two-wire signals supplied from the telephone terminal equipment through the line A and the line B to the switching network into transmitting side four-wire signals, including a pair of battery feeding and terminating resistors connected between power sources (GND and V BB ) and the line B and line A and a receiving side mirror circuit and transmitting side mirror circuit both connected between the lines B and A.

公开(公告)号：EP0360227B1

公开(公告)日：1995-06-07

申请号：EP89117313.0

申请日：1989-09-19

申请人： FUJITSU LIMITED

发明人： Itoh, Shin-ichi ,  Takato, Kenji ,  Iketani, Yozo ,  Yamamoto, Yuzo

IPC分类号： H04M19/00

CPC分类号： H04M19/005

公开(公告)号：EP0360227A3

公开(公告)日：1991-09-18

申请号：EP89117313.0

申请日：1989-09-19

申请人： FUJITSU LIMITED

发明人： Itoh, Shin-ichi ,  Takato, Kenji ,  Iketani, Yozo ,  Yamamoto, Yuzo

IPC分类号： H04M19/00

CPC分类号： H04M19/005

摘要： Disclosed is a terminating circuit in a battery feed circuit of an electronic exchange system. The battery feed circuit comprises two transconductance amplifiers connected by a coupling capacitor, for supplying a direct current through a ring terminal and a tip terminal to a load. Each of the transconductance amplifiers comprises an operational amplifier (21); a resistor (R F ) connected between the output end of the operational amplifier and the tip terminal or the ring terminal, and an impedance unit connected between the inverting input terminal of the operational amplifier and the output end. The impedance unit has an impedance determined in such a way that the required terminating impedance of the battery feed circuit when viewed from the tip terminal and the ring terminal is formed only by the internal elements including the impedance means and the resistor, whereby an external larger-size capacitance capacitor for matching becomes unnecessary.

公开(公告)号：EP0295680A3

公开(公告)日：1990-12-05

申请号：EP88109651.5

申请日：1988-06-16

申请人： FUJITSU LIMITED

发明人： Takato, Kenji ,  Tojo, Toshiro ,  Kinoshita, Kazumi ,  Yamamoto, Yuzo

IPC分类号： H04M19/00

CPC分类号： H04M19/005

摘要： A battery feed circuit including a main battery feed part and its peripheral circuits provided in a line circuit of a switching system. The peripheral circuits include the following:
    first, a means for forming a low impedance with respect to in-phase signals, simply realized by a capacitor (30);
    second, a bias circuit (2) able to suppress the entry of power source noise and easily switch magnitudes of bias voltages and polarities, realized by a bias voltage generating means, a buffer means, and an AC bypass capacitor;
    third, a battery feed current control circuit (3-A to 3-D) able to suppress overflow of battery feed current when the distance to the subscriber is short, which detects an overcurrent component above a predetermined value, and, in accordance with same, changes the bias voltage;
    fourth, a battery feed current supervising circuit (4-A,4-B) able to detect current in both the forward and reverse directions, realized by an emitter-follower pair and a voltage/current converting resistor;
    fifth, a circuit (5-A,5-B) for detecting bidirectional battery feed currents at a high precision, which is formed by forward direction and reverse direction current detection means provided with (V BE ) cancelling means; and
    sixth, an overcurrent protection circuit (6-A,6-B), which changes the voltage applied between the inputs (+,-) of a transconductance amplifier forming the main battery feed part in accordance with an excess voltage.

公开(公告)号：EP0295683A3

公开(公告)日：1990-04-18

申请号：EP88109654.9

申请日：1988-06-16

申请人： FUJITSU LIMITED

发明人： Tojo, Toshiro ,  Takato, Kenji ,  Kinoshita, Kazumi ,  Yamamoto, Yuzo

IPC分类号： H04M3/18 ,  H04M19/00 ,  H02H9/02

CPC分类号： H04M3/18 ,  H02H9/025 ,  H04M19/001

摘要： A protection circuit for a battery feed circuit used in a switching system. The protection circuit is comprised of:
    a supervising circuit (11) for detecting an abnormal current flowing through a battery feed resistor (R₁); and a voltage limiting circuit (12) for clamping a voltage across the battery feed resistor (R₁) when the abnormal current is detected. Further, a control circuit (13) is employed for stopping an operational amplifier (OP₁) when the abnormal current is detected. The operational amplifier (OP₁) constitutes a conventional battery feed circuit and is connected, at the output thereof, with the base of a battery feed transistor (Q₁) connected between a subscriber's line and the battery feed resistor (R₁).

公开(公告)号：EP0295683A2

公开(公告)日：1988-12-21

申请号：EP88109654.9

申请日：1988-06-16

申请人： FUJITSU LIMITED

发明人： Tojo, Toshiro ,  Takato, Kenji ,  Kinoshita, Kazumi ,  Yamamoto, Yuzo

IPC分类号： H04M3/18 ,  H04M19/00 ,  H02H9/02

CPC分类号： H04M3/18 ,  H02H9/025 ,  H04M19/001

摘要： A protection circuit for a battery feed circuit used in a switching system. The protection circuit is comprised of:
    a supervising circuit (11) for detecting an abnormal current flowing through a battery feed resistor (R₁); and a voltage limiting circuit (12) for clamping a voltage across the battery feed resistor (R₁) when the abnormal current is detected. Further, a control circuit (13) is employed for stopping an operational amplifier (OP₁) when the abnormal current is detected. The operational amplifier (OP₁) constitutes a conventional battery feed circuit and is connected, at the output thereof, with the base of a battery feed transistor (Q₁) connected between a subscriber's line and the battery feed resistor (R₁).

摘要翻译： 一种用于交换系统中的电池馈电电路的保护电路。 保护电路包括：用于检测流过电池馈电电阻器（R1）的异常电流的监控电路（11）; 以及用于在检测到异常电流时夹紧电池馈送电阻器（R1）两端的电压的限压电路（12）。 此外，当检测到异常电流时，采用控制电路（13）来停止运算放大器（OP1）。 运算放大器（OP1）构成传统的电池馈电电路，并在其输出端连接有连接在用户线路和电池馈电电阻器（R1）之间的电池馈送晶体管（Q1）的基极。