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6 条记录 (耗时 0.042 秒)

    Automatic cable balancing network
    4.
    发明授权
    Automatic cable balancing network 失效
    自动电缆平衡网络

    公开(公告)号：US4096362A

    公开(公告)日：1978-06-20

    申请号：US808091

    申请日：1977-06-20

    申请人： Charles David Crawford

    发明人： Charles David Crawford

    IPC分类号： H03H11/30 ,  H04B1/58 ,  H04Q3/00 ,  H04B1/52

    CPC分类号： H04B1/582 ,  H03H11/30 ,  H04Q3/00

    摘要： A hybrid circuit for coupling a bidirectional telephone cable to two unidirectional cables is balanced automatically by employing an adjustable balance network and a control circuit. Optimum adjustment of the balance network is achieved over a frequency band of interest by employing a signal source having one or more frequency components within the frequency band of interest and by generating signals for controlling magnitude and phase components in the balance network. The magnitude control signal is representative of the difference between the absolute magnitudes of signals detected at the bidirectional cable connection to the hybrid and at the balance network connection to the hybrid in the frequency band of interest. Signals for controlling the phase components of the balance network are representative of the difference between the absolute magnitudes of the detected signals modified by a first prescribed weighting function less a component proportional to the phase difference between the detected signals modified by a second prescribed weighting function within the frequency band of interest. The weighting functions are obtained by employing a filter having a prescribed low-pass characteristic. The component values of the filter are determined by the locations of adjustable pole(s) and/or zero(s) within the frequency band. The filter characteristic may be adjusted during the balance process further to optimize the balance network adjustments.

    摘要翻译： 用于将双向电话电缆耦合到两个单向电缆的混合电路通过采用可调平衡网络和控制电路自动平衡。 平衡网络的最佳调整是通过在感兴趣的频带内采用具有一个或多个频率分量的信号源，并产生用于控制平衡网络中的幅度和相位分量的信号来实现的。 幅度控制信号表示在与混合信号的双向电缆连接处和在感兴趣的频带中与混合信号的平衡网络连接处检测到的信号的绝对值之间的差异。 用于控制平衡网络的相位分量的信号代表由第一规定加权函数修正的检测信号的绝对值之差，该第一规定加权函数的绝对值与通过第二规定加权函数修改的检测信号之间的相位差成比例的分量 感兴趣的频段。 通过采用具有规定的低通特性的滤波器来获得加权函数。 滤波器的分量值由频带内可调节极点和/或零点的位置决定。 过滤器特性可以在平衡过程中进一步调整，以优化平衡网络调整。

    Optical Gray to binary code converter
    5.
    发明授权
    Optical Gray to binary code converter 失效
    光学灰色到二进制码转换器

    公开(公告)号：US4055841A

    公开(公告)日：1977-10-25

    申请号：US665332

    申请日：1976-03-09

    申请人： Charles David Crawford

    发明人： Charles David Crawford

    IPC分类号： H03M7/00 ,  H03K13/24

    CPC分类号： H03M7/001

    摘要： Signals representative of information bits are converted from one binary code, for example, Gray code, to another binary code, for example, conventional binary, and vice versa, by advantageously employing optical couplers in conjunction with buffer amplifiers. The optical couplers include light emitting diodes and associated phototransistors which are uniquely connected in circuit relationship with the outputs of the buffer amplifiers to effect the desired code conversions.

    摘要翻译： 通过有利地使用光耦合器与缓冲放大器相结合，代表信息位的信号从一个二进制码（例如，格雷码）转换成另一个二进制码，例如常规二进制，反之亦然。 光耦合器包括发光二极管和相关的光电晶体管，它们与缓冲放大器的输出电路关系唯一地连接以实现期望的代码转换。

    Test apparatus for obtaining impedance settings for hybrid balance networks
    6.
    发明授权
    Test apparatus for obtaining impedance settings for hybrid balance networks 失效
    用于获得混合平衡网络阻抗设置的测试装置

    公开(公告)号：US4096361A

    公开(公告)日：1978-06-20

    申请号：US808092

    申请日：1977-06-20

    申请人： Charles David Crawford

    发明人： Charles David Crawford

    IPC分类号： H04B3/46 ,  H04B1/52

    CPC分类号： H04B3/46

    摘要： Impedance settings are obtained automatically for manually adjusting a network to obtain a driving point impedance substantially equal to a particular unknown impedance. Discrete impedance settings for setting up, for example, a manually adjustable hybrid balance network are obtained by employing a hybrid network, a noise signal source, at least first and second automatically adjustable balance networks and at least first and second control circuits. An impedance to be matched, for example, a 2-wire telephone cable, is connected to the hybrid. Signals detected at the cable and at the inputs to the respective balance networks are employed to generate control signals for adjusting impedance elements in the automatically adjustable balance networks. Impedance elements in the first balance network are continuously adjusted to match substantially exactly the impedance of the cable. Then, the most sensitive of the corresponding control signals is rounded off to a discrete value and supplied to adjust a corresponding discretely adjustable impedance element in the at least second adjustable balance network. The second control circuit then generates signals for adjusting the remaining impedance elements in the second balance network to obtain the most optimum driving point impedance to match the cable impedance. Values of the impedance control are displayed in binary form to be used by a craftsperson for setting up a corresponding manually adjustable balance network to match the particular cable connected to the hybrid.

    摘要翻译： 自动获得阻抗设置，手动调整网络以获得基本上等于特定未知阻抗的驱动点阻抗。 通过采用混合网络，噪声信号源，至少第一和第二自动可调平衡网络以及至少第一和第二控制电路来获得用于设置例如可手动调节的混合平衡网络的离散阻抗设置。 要匹配的阻抗，例如2线电话线连接到混合电路。 在电缆和各个平衡网络的输入处检测到的信号被用于产生用于调整自动可调平衡网络中的阻抗元件的控制信号。 连续调节第一平衡网络中的阻抗元件，使其与电缆的阻抗基本上完全一致。 然后，相应的控制信号的最敏感的四舍五入到一个离散的值，并被提供以调整该至少第二可调平衡网络中相应的离散可调的阻抗元件。 然后，第二控制电路产生用于调整第二平衡网络中的剩余阻抗元件的信号，以获得最佳驱动点阻抗以匹配电缆阻抗。 阻抗控制的值以二进制形式显示，以供技术人员用于设置相应的可手动调节的平衡网络以匹配连接到混合动力的特定电缆。