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51. 发明授权

US4961219A Circuit for synthesizing an impedance across the tip and ring leads of a telephone line circuit 失效
标题翻译：用于合成电话线电路的尖端和环形引线上的阻抗的电路
公开(公告)号：US4961219A
公开(公告)日：1990-10-02
申请号：US445827
申请日：1989-12-04
申请人： Lalit O. Patel
发明人： Lalit O. Patel
IPC分类号： H04M1/76 , H04M19/00
CPC分类号： H04M19/005 , H04M1/76
摘要： A circuit for synthesizing an impedance across the tip and ring leads of a telephone line circuit is disclosed. The circuit includes tip drive and ring drive amplifiers connected to the tip and ring leads respectively, of a subscriber loop. The tip drive and ring drive amplifier circuits are arranged to convert feed voltage from a central office battery to feed current to drive the subscriber loop. A common-mode amplifier circuit connected between the tip and the ring leads senses the voltage dropped across the subscriber loop and outputs a control voltage to the tip and ring drive amplifiers, offsetting the feed currents applied to the subscriber loop. A differential amplifier circuit also connected to the tip and ring leads of the subscriber loop, detects a voltage difference between the tip lead and the ring lead and converts the detected differential voltage into a single ended output voltage of a specific gain. The output voltage from the differential amplifier circuit is coupled to a feedback circuit via a series connected resistor and capacitor network. The feedback circuit receives the differential amplifier output voltage that is modified by the values of the resistor and capacitor network and develops a pair of balanced output signals which are equal in amplitude but 180 degrees out of phase with each other. Each of the output signals is connected to a respective one of the tip drive and ring drive amplifier circuits where, an input impedance equal to the impedance of the subscriber loop is derived at the tip and ring leads.
摘要翻译：公开了一种用于合成电话线电路的尖端和环形引线上的阻抗的电路。该电路包括分别连接到用户回路的尖端和环形引线的尖端驱动和环形驱动放大器。顶端驱动器和环形驱动放大器电路被布置成将来自中心局电池的馈电电压转换为馈电电流以驱动用户环路。连接在尖端和环形引线之间的共模放大器电路检测在用户回路上下降的电压，并将控制电压输出到尖端和环形驱动放大器，抵消施加到用户回路的馈电电流。差分放大器电路也连接到用户环路的尖端和环形引线，检测尖端引线和环形引线之间的电压差，并将检测到的差分电压转换为特定增益的单端输出电压。来自差分放大器电路的输出电压通过串联的电阻和电容网络耦合到反馈电路。反馈电路接收由电阻和电容网络的值修改的差分放大器输出电压，并产生一对平衡输出信号，它们的幅度相等，但彼此相差180度。每个输出信号连接到尖端驱动和环形驱动放大器电路中的相应一个，其中在尖端和环形引线处导出等于用户环路阻抗的输入阻抗。

52. 发明授权

US4856058A Office line interface circuits 失效
标题翻译：办公线路接口电路
公开(公告)号：US4856058A
公开(公告)日：1989-08-08
申请号：US188101
申请日：1988-04-27
申请人： Yasuji Sato , Fumio Hino
发明人： Yasuji Sato , Fumio Hino
IPC分类号： H04M1/58 , H04M1/76 , H04M7/04 , H04M9/00 , H04Q3/58
CPC分类号： H04M1/76 , H04M1/58 , H04M9/006
摘要： An office line interface circuit includes a DC circuit for extracting a DC signal component from the office line current, an AC circuit for extracting an AC signal component from the office line current to supply the extracted AC signal component to the receiver of a telephone set, an impedance circuit switchably connected to the office line, and a switching circuit for connecting the impedance circuit to the office line when the extracted DC signal component exceeds a predetermined level to maintain at a substantially constant value the impedance of the office line as viewed from the telephone set. With this interface circuit, the sidetone preventing circuit for the telephone system can operate satisfactorily without complicating the construction under any office line condition.
摘要翻译：办公室线路接口电路包括用于从办公室线路电流提取DC信号分量的DC电路，AC电路，用于从办公室线路电流提取AC信号分量，以将所提取的AC信号分量提供给电话机的接收机，可切换地连接到办公室线路的阻抗电路以及当所提取的直流信号分量超过预定电平时将阻抗电路连接到办公室线路以将从办公室线路观察到的办公室线路的阻抗维持在基本恒定的值的开关电路电话机使用该接口电路，电话系统的侧音防止电路可以令人满意地运行，而不会使任何办公线条件下的结构复杂化。

53. 发明授权

US4453037A Loop length compensation circuit 失效
标题翻译：环路长度补偿电路
公开(公告)号：US4453037A
公开(公告)日：1984-06-05
申请号：US335142
申请日：1981-12-28
申请人： Michael B. Terry
发明人： Michael B. Terry
IPC分类号： H04M1/76 , H04B3/36
CPC分类号： H04M1/76
摘要： A compensation circuit (10) controls the gain of transmit and receive amplifiers (47), (49) as a function of a residual input current (I.sub.res). Circuit (10) includes a constant current source (24) which is connected to produce mirrored constant currents in transistors (26) and (28). The residual current is passed through a resistor (R.sub.loop) to produce a reference voltage. The constant current from the transistor (26) is divided with the first part of the current passing through the resistor (R.sub.loop) and the second part of the current passing through a resistor (50) and a transistor (54). The transistor (54) is connected in a mirror configuration with a transistor (58). When the residual current increases, the current mirrored to transistor (58) decreases. A transistor (32) is connected in parallel with the transistor (58) to receive the remaining current from the transistor (28) which is not drawn by the transistor (58). The transistor (32) serves as the master side of a mirror circuit having slave transistors (38) and (42). The current mirrored to the transistors (38), (42) is drawn from the amplifiers (47), (49) wherein the current through the amplifiers is proportional to the gain thereof. Thus, the gain of the amplifiers is inversely proportional to the residual current thereby compensating the amplifier gain for the length of the telephone line.
摘要翻译：补偿电路（10）根据剩余输入电流（Ires）控制发射和接收放大器（47），（49）的增益。电路（10）包括恒流源（24），其连接以在晶体管（26）和（28）中产生镜像恒定电流。剩余电流通过电阻（Rloop）以产生参考电压。来自晶体管（26）的恒定电流与通过电阻器（R loop）的电流的第一部分和通过电阻器（50）和晶体管（54）的电流的第二部分分开。晶体管（54）以反射镜配置与晶体管（58）连接。当剩余电流增加时，镜像到晶体管（58）的电流减小。晶体管（32）与晶体管（58）并联连接，以从晶体管（28）接收未被晶体管（58）吸引的剩余电流。晶体管（32）用作具有从晶体管（38）和（42）的镜电路的主侧。从放大器（47），（49）中抽出与晶体管（38），（42）镜像的电流，其中通过放大器的电流与其增益成比例。因此，放大器的增益与剩余电流成反比，从而补偿了电话线长度的放大器增益。

54. 发明授权

US4442325A Switchable incremental attenuation for telephone line interface 失效
标题翻译：电话线接口可切换增量衰减
公开(公告)号：US4442325A
公开(公告)日：1984-04-10
申请号：US528668
申请日：1983-09-02
申请人： Noel C. McDermott
发明人： Noel C. McDermott
IPC分类号： H04M1/76
CPC分类号： H04M1/76
摘要： A self-contained switchable, incremental attenuator device for interposing in a two line power circuit to attenuate the power level for proper power matching. The device includes a series of modulized, individually switchable attenuator circuits of differing attenuation values mounted upon a pluggable card for interfacing with input and output connectors of a circuit. The attenuation values of the sections are selected such that manipulating the switches will allow attenuation of the power level in the circuit by an integral multiple of a given base incremental value within a given range. The attenuator device is designed to mate with a mounting device for holding the attenuator in contact with the circuit connectors.
摘要翻译：一种独立可切换的增量衰减器，用于插入两线电源电路，以衰减功率电平以进行适当的功率匹配。该装置包括一系列模块化的可单独切换的衰减器电路，其不同的衰减值安装在可插拔卡上，用于与电路的输入和输出连接器进行接口。选择这些部分的衰减值使得操纵开关将允许电路中的功率电平衰减给定范围内给定基本增量值的整数倍。衰减器装置被设计成与用于保持衰减器与电路连接器接触的安装装置配合。

55. 发明授权

US4400588A Electronic voice network for a telephone subscriber's substation 失效
标题翻译：用于电话用户变电站的电子语音网络
公开(公告)号：US4400588A
公开(公告)日：1983-08-23
申请号：US273700
申请日：1981-06-15
申请人： William Stobbs , Charles Hines , Rickey W. Light
发明人： William Stobbs , Charles Hines , Rickey W. Light
IPC分类号： H04M1/58 , H04M1/60 , H04M1/76 , H04M1/00
CPC分类号： H04M1/76 , H04M1/585
摘要： A circuit which performs loop supervision, transmit, receive, and transmit and receive regulation and sidetone balance. A loading circuit shunts excess current from the transmit and receive circuits under short loop conditions. The loading circuit also controls regulation of the transmit and receive circuits. Use of constant current power supplies external to the transmit and receive circuits prevents modulation of the power supplies.
摘要翻译：执行环路监控，发送，接收和发送以及接收调节和侧音平衡的电路。负载电路在短路环路条件下分流来自发射和接收电路的过电流。负载电路还控制发送和接收电路的调节。在发射和接收电路外部使用恒流电源可防止电源的调制。

56. 发明授权

US4176255A Adjustable impedance battery feed circuit 失效
标题翻译：可调阻抗电池供电电路
公开(公告)号：US4176255A
公开(公告)日：1979-11-27
申请号：US889859
申请日：1978-03-24
申请人： John A. Rudisill, Jr.
发明人： John A. Rudisill, Jr.
IPC分类号： H04M1/76 , H04M19/00
CPC分类号： H04M19/001 , H04M1/76
摘要： The magnitude of current supplied to a subscriber telephone loop during both loop start and ground start modes of operation is controllably limited by employing a battery feed circuit including an adjustable line build-out impedance. Resistors are controllably switched in or out of the battery feed circuit leads as a function of the potential developed across the line build-out impedance in a predetermined one of the battery feed circuit leads. Since the line build-out impedance being adjusted in value is within the detection loop, there is hysteresis in the switch points for switching the resistors in and out of the battery feed circuit leads. This hysteresis minimizes possible oscillation at the switch points and, therefore, minimizes development of unwanted signals on the subscriber loop. The use of an adjustable line build-out impedance further allows use of small resistance value, low wattage resistors as line build-out impedance elements. This improves overall efficiency and allows use of longer subscriber loops.
摘要翻译：在循环启动和接地启动操作模式期间提供给用户电话回路的电流的幅度通过采用包括可调线路建立阻抗的电池馈电电路来可控地受到限制。作为在预定的一个电池馈电电路引线中跨线路建立阻抗产生的电位的函数，可控制地将电阻器切换到电池馈送电路引线中或从电池馈电电路引线外引出。由于线路建立阻抗值被调整在检测环路内，所以在切换点中存在用于将电阻器切换到电池馈电电路引线中的滞后。该滞后将切换点处可能的振荡降至最小，因此可最大限度地减少用户回路上不需要的信号的发展。使用可调线路建立阻抗进一步允许使用小电阻值，低功率电阻作为线路建立阻抗元件。这提高了整体效率，并允许使用更长的用户环路。

57. 发明授权

US4143247A Automatic signal level adjusting circuits for use in telephone sets 失效
标题翻译：自动信号电平调节电路用于电话机
公开(公告)号：US4143247A
公开(公告)日：1979-03-06
申请号：US844969
申请日：1977-10-25
申请人： Makoto Yoshitoshi , Isao Kawashima , Hideo Kishimoto , Masaaki Terai , Kazumi Kato
发明人： Makoto Yoshitoshi , Isao Kawashima , Hideo Kishimoto , Masaaki Terai , Kazumi Kato
IPC分类号： H04M1/76 , H04M1/00
CPC分类号： H04M1/76
摘要： There are provided a current detecting resistance element connected in series with a loop for supplying current to a telephone set, a switching circuit including a three terminal semiconductor switching element connected to be ON.OFF controlled by the voltage drop across the resistance element, and an impedance element controlled by the ON.OFF operation of the switching element to be connected across the loop for adding AC loss.

58. 发明授权

US2858371A Telephone subscribers' apparatus 失效
标题翻译：电话用户设备
公开(公告)号：US2858371A
公开(公告)日：1958-10-28
申请号：US44018554
申请日：1954-06-29
申请人： GEN ELECTRIC CO LTD
发明人： FREDERICK JONES ARTHUR
IPC分类号： H04M1/76
CPC分类号： H04M1/76

59. 发明授权

US2785231A Telephone set with amplifier 失效
标题翻译：带放大器的电话机
公开(公告)号：US2785231A
公开(公告)日：1957-03-12
申请号：US41244854
申请日：1954-02-25
申请人： BELL TELEPHONE LABOR INC
发明人： CHASE ALBERT J
IPC分类号： H04M1/76
CPC分类号： H04M1/76

60. 发明授权

US1328326A Electric circuit 失效
标题翻译：电路
公开(公告)号：US1328326A
公开(公告)日：1920-01-20
申请号：US1913775632
申请日：1913-06-25
申请人： COOPER HEWITT PETER
发明人： COOPER HEWITT PETER
IPC分类号： H04M1/76
CPC分类号： H04M1/76

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