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    Paging amplifier for a key telephone system
    51.
    发明授权
    Paging amplifier for a key telephone system 失效
    寻呼放大器用于关键电话系统

    公开(公告)号：US4153820A

    公开(公告)日：1979-05-08

    申请号：US853001

    申请日：1977-11-18

    Applicant: Bruce R. Saxon

    Inventor： Bruce R. Saxon

    IPC: H03F3/26 ,  H04M3/40 ,  H03F3/20

    CPC classification number: H03F3/26

    Abstract: The amplifier includes an audio signal input means and a first pair of integrated circuit audio power amplifiers each having an inverting input and a non-inverting input. The inverting input of one of the first pair of amplifiers is coupled to the input means and the non-inverting input of the other of the first pair of amplifiers is coupled to the input means. A first load has one terminal coupled to the output of one of the first pair of amplifiers and the other terminal coupled to the output of the other of the first pair of amplifiers. A second pair of integrated circuit audio power amplifiers each having an inverting input and a non-inverting input. The inverting input of one of the second pair of amplifiers is coupled to the input means and the non-inverting input of the other of the second pair of amplifiers is coupled to the input means. A second load has one terminal coupled to the output of one of the second pair of amplifiers and the other terminal coupled to the output of the other of the second pair of amplifiers. The first and second loads provide positive and negative amplified audio output signals for the paging amplifier.

    Abstract translation: 放大器包括音频信号输入装置和第一对集成电路音频功率放大器，每个具有反相输入和非反相输入。 第一对放大器之一的反相输入耦合到输入装置，并且第一对放大器中另一个放大器的非反相输入耦合到输入装置。 第一负载具有耦合到第一对放大器之一的输出的一个端子和耦合到第一对放大器中另一个的输出的另一个端子。 每个具有反相输入和非反相输入的第二对集成电路音频功率放大器。 第二对放大器之一的反相输入耦合到输入装置，并且第二对放大器中的另一对放大器的非反相输入耦合到输入装置。 第二负载具有耦合到第二对放大器之一的输出的一个端子和耦合到第二对放大器中的另一对放大器的输出的另一个端子。 第一和第二负载为寻呼放大器提供正和负放大的音频输出信号。

    Monobus interface circuit using opto-coupled hybrids
    52.
    发明授权
    Monobus interface circuit using opto-coupled hybrids 失效
    使用光耦合混合器的MONOBUS接口电路

    公开(公告)号：US4045615A

    公开(公告)日：1977-08-30

    申请号：US688787

    申请日：1976-05-21

    Applicant: Dennis Bryan James ,  Chao Kai Liu ,  Douglas Charles Smith

    Inventor： Dennis Bryan James ,  Chao Kai Liu ,  Douglas Charles Smith

    IPC: H04M3/40 ,  H04M3/56

    CPC classification number: H04M3/56 ,  H04M3/40

    Abstract: In order to reduce the signal loss in a telephone line switching and conferencing system there is interposed between each line and the switching matrix a monobus port circuit arranged to convert a transmitted telephone signal into an equivalent current source. An opto-coupled hybrid replaces the port circuit transformer and serves to provide the desired voltage to current conversion. The currents from several monobus circuits are added in a bus resistor before distribution back to the individual monobus circuits as a voltage where the original signal is subtracted from the bus signal. The resultant signal is transmitted to the telephone receiver via the opto-coupled hybrid. When the switching matrix crosspoint resistance is negligible, the component of the bus voltage measured at the current source output which results from current generated from each port circuit is equal and opposite in magnitude to the voltage generated in the port circuit. In any given line these voltages cancel each other, thereby eliminating the feedback signal.

    Centralized network for a telephone station system
    53.
    发明授权
    Centralized network for a telephone station system 失效
    用于电话站系统的集中式网络

    公开(公告)号：US3819877A

    公开(公告)日：1974-06-25

    申请号：US20669271

    申请日：1971-12-10

    Applicant: BELL TELEPHONE LABOR INC

    Inventor： BLAHUT D ,  FRIEDMAN S ,  NASH D

    IPC: H04M1/60 ,  H04M3/40 ,  H04M13/00 ,  H04M19/00 ,  H04B3/36

    CPC classification number: H04M3/40 ,  H04M19/006

    Abstract: In a telephone station system the telephone apparatus is divided into two portions, a centralized network and one or more extensions or sets. The network is connected between the telephone sets and the line and may include, for example, a hybrid, amplifiers, automatic gain control circuitry and lightning protectors - all of which are shared by the satellite sets. The sets preferably include only the minimum required components such as a transmitter, a receiver, associated amplifiers, a tone ringer sounder and driver, and a dial.

    Abstract translation: 在电话系统中，电话设备被分成两部分，集中式网络和一个或多个扩展或集合。 网络连接在电话机和线路之间，并且可以包括例如混合，放大器，自动增益控制电路和防雷器 - 所有这些都由卫星组共享。 这些组优选地仅包括最小要求的组件，例如发射器，接收器，相关联的放大器，铃声发声器和驱动器以及拨盘。

    Switching device for telephone instruments, adapted to alternately be used as lowspeaking and loudspeaking telephones
    54.
    发明授权
    Switching device for telephone instruments, adapted to alternately be used as lowspeaking and loudspeaking telephones 失效
    适用于电话仪器的切换装置，适用于低噪声和扬声器电话

    公开(公告)号：US3772472A

    公开(公告)日：1973-11-13

    申请号：US3772472D

    申请日：1971-02-16

    Applicant: BLOMBERG K

    Inventor： BLOMBERG K

    IPC: H04M1/62 ,  H04M3/40

    CPC classification number: H04M1/62

    Abstract: A switching device for telephone instruments for enabling said instrument to be used alternately as a lowspeaking telephone and as a loudspeaking telephone compriisng a base support unit for said telephone instrument, said base support unit being provided with switching contacts, said switching contacts being adapted to switch over the telephone from low-speaking to loudspeaking condition when the instrument is placed on to said support unit.

    Abstract translation: 一种电话设备的开关装置，用于使所述仪器交替地用作低语音电话和作为用于所述电话设备的基座支持单元的扬声电话，所述基座支撑单元设置有开关触点，所述开关触点适于切换 在将仪器放置在所述支撑单元上时，通过电话从低扬声到扬声状态。

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