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1.发明授权Anti-larsen-effect arrangement in a telephone station equipped with a loudspeaker 失效在配有扬声器的电话台中进行防扩散效应布置
公开(公告)号：US4484034A
公开(公告)日：1984-11-20
申请号：US500799
申请日：1983-06-07
CPC分类号： H04M9/08
摘要： An anti-Larsen circuit for a telephone station in which the listening channel comprises an automatic listening level control circuit, suitably of the type comprising a variable attenuator circuit, a pulse-width modulator and a threshold detector which supplies compression pulses. The transmission channel comprises a circuit for rendering the transmission channel operative or inoperative and also a control circuit. Actuation takes place above a sound-level threshold S.sub.1 and a de-activation below a sound-level threshold S.sub.2 which is smaller than S.sub.1.
摘要翻译： 一种用于电话台的反拉森电路，其中听音通道包括自动聆听电平控制电路，适合于包括可变衰减器电路，脉冲宽度调制器和提供压缩脉冲的阈值检测器的类型。 传输信道包括用于使传输信道操作或不起作用的电路，以及控制电路。 在声级阈值S1之上进行动作，并且在小于S1的声级阈值S2之下进行去激活
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公开(公告)号：US4386236A
公开(公告)日：1983-05-31
申请号：US244359
申请日：1981-03-16
CPC分类号： H03K7/08 , H03G3/20 , H04M1/6033
摘要： This arrangement comprises a controllable attenuation circuit of the voice signal received, a pulse-duration modulator which produces pulses the duration of which is modulated by the voice signal supplied by the controllable attenuation circuit, an overshoot detection circuit which produces from the modulated pulses a compression pulse each time it is detected that the amplitude of the modulated voice signal reaches a certain threshold, the compression signal produced by the said overshoot detection circuit being applied in the attenuation circuit to an integrating circuit which produces the attenuation control signal. The amplifier of the loudspeaker receives the modulated signal.
摘要翻译： 这种布置包括接收到的语音信号的可控衰减电路，脉冲持续时间调制器，产生其持续时间由可控衰减电路提供的语音信号调制的脉冲，过冲检测电路从调制脉冲产生压缩 每当检测到调制语音信号的幅度达到一定阈值时，由所述过冲检测电路产生的压缩信号被施加到衰减电路中，以产生衰减控制信号的积分电路。 扬声器的放大器接收调制信号。
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3.发明授权
公开(公告)号：US4454384A
公开(公告)日：1984-06-12
申请号：US376888
申请日：1982-05-10
CPC分类号： H04M9/08
摘要： "Hands free" telephone sets in which there is connected in parallel with the terminals (A) and (B) of a first path (C.sub.1) comprising the coupling circuit of the telephone set in series with a controllable amplifier (11) of the receiving path (6), a second path (C.sub.2) comprising a controllable amplifier (12) which is controlled by a linear regulator (13) which keeps its output signal constant. The gains of the two amplifiers (11) and (12) respond to each other. A device is provided so as to ensure that the gain in the second path remains higher than the gain in the first path. A third controllable amplifier (5) is provided between the microphone (4) and the input terminal (A) which is used in common by the first and second paths; the said means (14) are adjusted in such a way that the electro-acoustic loop which is closed by the second path (C.sub.2) is permanently the source of non-annoying oscillations. By inducing a gain variation of the second amplifier (6) a gain variation in the opposite sense is produced in the receiving path, it being possible for these two variations to have accurately the same amplitudes.
摘要翻译： “免提”电话机与第一路径（C1）的端子（A）和（B）并联连接，第一路径（C1）包括电话机的耦合电路与接收机的可控放大器（11）串联 路径（6），包括由可保持其输出信号恒定的线性调节器（13）控制的可控放大器（12）的第二路径（C2）。 两个放大器（11）和（12）的增益相互响应。 提供了一种装置，以确保第二路径中的增益保持高于第一路径中的增益。 第三可控放大器（5）设置在麦克风（4）和输入端（A）之间，其通过第一和第二路径共同使用; 所述装置（14）被调节成使得由第二路径（C2）闭合的电声回路永久地是非烦人的振荡源。 通过诱导第二放大器（6）的增益变化，在接收路径中产生相反意义上的增益变化，这两个变化可能具有准确相同的幅度。
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公开(公告)号：US4174467A
公开(公告)日：1979-11-13
申请号：US878667
申请日：1978-02-17
CPC分类号： H04M19/023
摘要： A ringing signal generator for generating a ringing current in a subscriber's line uses a line current inverter controlled by means of a pulse code modulated signal obtained by encoding a sinusoidal ringing signal by means of a delta modulator at a sampling frequency which considerably exceeds the frequency of the ringing current.
摘要翻译： 用于在用户线路中产生振铃电流的振铃信号发生器使用线路电流逆变器，该线路电流逆变器通过采用增益调制器对正弦振铃信号进行编码而得到的脉冲编码调制信号，该脉冲编码调制信号的采样频率大大超过频率 振铃电流。
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公开(公告)号：US4827472A
公开(公告)日：1989-05-02
申请号：US764161
申请日：1985-08-09
IPC分类号： H04B3/23
摘要： An echo canceller designed to cancel an echo signal [g(t)] generated in a send path (7) by a signal [f(t)] applied to a receive path (1) contains a subtractor (9) whose positive terminal receives a signal derived from the echo signal and whose negative terminal receives the output signal from a transversal filter (10) provided with means (12) for adjusting the filter coefficients in such a way that the component due to the echo signal is cancelled at the output of the subtractor (9).This echo canceller comprises a delta encoder (14) for encoding at a sampling rate 1/T the signal f(t) entering the receive path (1) and for supplying at the input of the transversal filter (10) a delta-encoded signal (.DELTA.F.sub.n), a circuit (22) for forming at the sampling rate 1/T the difference signal (d.sub.n) between two consecutive samples of the signal entering the send path (7) and for applying this signal to the positive terminal of the subtractor (9), and finally an integrator (13) connected to the output of the subtractor (9) and supplying the output signal of the send path (7).
摘要翻译： 设计为通过施加到接收路径（1）的信号[f（t）]消除在发送路径（7）中生成的回波信号[g（t）]的回波消除器包含一个减法器（9），其正端子接收 从回波信号导出的信号，其负极端子接收来自横向滤波器（10）的输出信号，该横向滤波器（10）具有用于调整滤波器系数的装置，使得由于回波信号的分量在输出端被消除 的减法器（9）。 该回波消除器包括用于以采样率1 / T对进入接收路径（1）的信号f（t）进行编码并在横向滤波器（10）的输入处提供增量编码信号的增量编码器（14） （DELTA Fn），用于以采样率1 / T形成进入发送路径（7）的信号的两个连续样本之间的差分信号（dn）并将该信号施加到该信号的正端子的电路（22） 减法器（9），最后是与减法器（9）的输出端连接并提供发送路径（7）的输出信号的积分器（13）。
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6.发明授权Arrangement for avoiding annoying sustained oscillations in a closed-loop system and loud-speaking telephone set employing this arrangement 失效用于避免使用这种布置的闭环系统和大声电话机中的烦人的持续振荡的布置
公开(公告)号：US4453039A
公开(公告)日：1984-06-05
申请号：US372430
申请日：1982-04-28
摘要： Circuitry for avoiding sustained oscillations in a closed-loop system, particularly a loud-speaking telephone set. The object is to avoid sustained annoying oscillations in a looped system, such as a looped electro-acoustic system or a control system. The circuitry comprises a variable-gain amplifier (11) incorporated in a first path (C.sub.1) which forms part of the loop. Connected between the input terminal (A) and the output terminal (B) of the said first path is a second path (C.sub.2) having at least one part which is separate from the first path. A device is provided to ensure that the gain in the second path remains higher than the gain in the first path in the overall frequency band where the oscillations are liable to be produced. A signal (W) formed in the part of the second path which is separate from the first path is applied to the input of a linear regulator 13, which controls the variable-gain amplifier (11) of the first path and a variable-gain amplifier (12) of the second path so as to keep the signal at the input of the regulator (13) constant for a certain value of the signal (W) formed in the second path.
摘要翻译： 用于避免闭环系统中的持续振荡的电路，特别是扬声电话机。 目的是避免环路系统中的持续烦人的振荡，例如循环的电声系统或控制系统。 该电路包括并入在形成环路的一部分的第一路径（C1）中的可变增益放大器（11）。 连接在所述第一路径的输入端子（A）和输出端子（B）之间的是具有与第一路径分开的至少一个部分的第二路径（C2）。 提供了一种装置，以确保第二路径中的增益保持高于容易产生振荡的整个频带中的第一路径中的增益。 形成在与第一路径分离的第二路径的部分中的信号（W）被施加到线性调节器13的输入端，线性调节器13控制第一路径的可变增益放大器（11）和可变增益 放大器（12），以便在形成在第二路径中的信号（W）的一定值上保持稳压器（13）输入端的信号是恒定的。
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7.发明授权Time-division multiplex communication system for connecting two-wire line circuits in time-division multiplex 失效时分复用通信系统，用于在时分复用中连接双线线路电路
公开(公告)号：US4187400A
公开(公告)日：1980-02-05
申请号：US887434
申请日：1978-03-16
摘要： Two time division multiplex switches connected to the ends of a time-division multiplex bus are controlled so that they are closed during a periodically repeated time interval. Connected to the terminals of each two-wire line circuit is a capacitor and a switch, which is synchronously controlled with the time-division multiplex switches so that during each time interval the capacitor is charged to a voltage present on the time-division multiplex bus and that during the successive time intervals the discharge time constant of the capacitor is so long that the voltage of the electrodes of the capacitor remains substantially constant. The voltage is connected across the impedance of the corresponding two-wire line circuit.
摘要翻译： 连接到时分多路复用总线两端的两个时分复用开关被控制成在周期性重复的时间间隔期间它们被关闭。 连接到每个双线线路电路的端子是电容器和开关，其与时分复用开关同步控制，使得在每个时间间隔期间，电容器被充电到时分复用总线上存在的电压 并且在连续的时间间隔期间，电容器的放电时间常数如此长，使得电容器的电极的电压基本保持不变。 电压连接在相应的双线线路电路的阻抗上。
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公开(公告)号：US4481463A
公开(公告)日：1984-11-06
申请号：US374123
申请日：1982-05-03
CPC分类号： H04M19/005
摘要： A current mirror circuit for weighting a plurality of input currents and for forming their sum, the weighting coefficients of the input currents each being determined by the ratio between the value of first resistors present between an input terminal and a power supply terminal, and the value of a second resistor. Such circuits are suitable for use in subscriber line interface circuits in which the weighted sum is to be formed of the currents entering and leaving the subscriber's line with a precise adjustment of the weighting coefficients.
摘要翻译： 一种用于加权多个输入电流并形成它们的和的电流镜电路，每个由输入端和电源端之间存在的第一电阻的值之间的比值确定的输入电流的加权系数和值 的第二电阻器。 这种电路适用于用户线路接口电路，其中加权和将由进入和离开用户线路的电流形成，并精确地调整加权系数。
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公开(公告)号：US4356354A
公开(公告)日：1982-10-26
申请号：US159732
申请日：1980-06-16
CPC分类号： H04M19/005
摘要： For feeding a telephone subscriber's line without the use of a transformer, this junctor comprises a symmetrical amplifier whose two input terminals receive two negative feedback voltages derived from a weighted sum current of the currents entering and leaving the subscriber's line. To form this weighted sum current, use is made of a current mirror whose summing and input terminals are connected respectively to one terminal of the supply source and to the corresponding supply terminal of the amplifier, and a voltage divider connected between the output of the current mirror and the other terminal of the supply source and whose intermediate terminal is connected to the other supply terminal of the amplifier. The voltage ratio of the voltage divider is equal to the current ratio of the current mirror. The voltage at the ends of the voltage divider is applied to a voltage follower which is regulated to provide the weighted sum current with the desired amplitude.
摘要翻译： 为了在不使用变压器的情况下馈送电话用户的线路，该连接器包括对称放大器，其两个输入端子接收从进入和离开用户线路的电流的加权和电流导出的两个负反馈电压。 为了形成该加权和电流，使用电流镜，其电流反射镜的求和和输入端子分别连接到电源的一个端子和放大器的相应电源端子，以及连接在电流输出端之间的分压器 反射镜和供电源的另一个端子，其中间端子连接到放大器的另一个供电端子。 分压器的电压比等于电流镜的电流比。 分压器端部的电压被施加到电压跟随器，电压跟随器被调节以提供具有期望幅度的加权和电流。
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公开(公告)号：US4211896A
公开(公告)日：1980-07-08
申请号：US949715
申请日：1978-10-10
CPC分类号： H04M19/001 , H04M19/023
摘要： Subscriber's circuit for connecting a subscriber's line to a telephone exchange, comprising a symmetrical amplifier which is arranged between two feed points having different potentials, the amplifier circuit having two input terminals and two output terminals, each one of the output terminals being connected to a wire of the subscriber's line and each input terminal of the symmetrical amplifier circuit being connected to an output of an associated digital-to-analog converter an input of which is connected to the one or to the other feed point by means of a change-over switch, the change-over switches being controlled in phase opposition by a binary digital signal which characterizes a voltage desired for the subscriber's line and which is derived from a digital signal generator under the control of the telephone exchange.
摘要翻译： 用户电路，用于将用户线路连接到电话交换机，包括布置在具有不同电位的两个馈电点之间的对称放大器，放大器电路具有两个输入端子和两个输出端子，每个输出端子连接到电线 的用户线路，并且对称放大器电路的每个输入端子连接到相关联的数模转换器的输出，其输入端通过转换开关连接到一个或另一馈电点 ，转换开关通过二进制数字信号进行相位控制，二进制数字信号表征用户线路所需的电压，并且在电话交换机的控制下从数字信号发生器导出。
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