Dynamic range modifying circuits utilizing variable negative resistance
    41.
    发明授权
    Dynamic range modifying circuits utilizing variable negative resistance 失效
    动态范围修正电路采用可变负电阻

    公开(公告)号:US3909733A

    公开(公告)日:1975-09-30

    申请号:US46983774

    申请日:1974-05-14

    发明人: DOLBY RAY MILTON

    CPC分类号: H03G9/025 G11B23/0007

    摘要: Dynamic range modifying circuits, namely compressors and expanders, are disclosed in which series connected circuits respond to current or voltage drive to provide voltage or current output. One circuit has characteristics which do not vary with dynamic range and contributes a component to the output having dynamic range linearity relative to the input. A second circuit has variable impedance characteristics and contributes a component which does not have dynamic range linearity relative to the input and which effects the dynamic range modification. Devices are described in which the variable impedance characteristics include effective negative resistance which is itself varied and is shunted by a variable reactance. Devices are also described in which the second circuit is a two terminal network which responds to the current between the two terminals to determine the voltage therebetween and wherein the voltage is derived either by way of a variable filter which acts to restrict the voltage or by way of multiple paths including filters and limiters.

    摘要翻译: 公开了动态范围修改电路,即压缩机和扩展器,其中串联的电路响应电流或电压驱动以提供电压或电流输出。 一个电路具有不随动态范围变化的特性,并且对于具有相对于输入的动态范围线性的输出贡献一个分量。 第二电路具有可变阻抗特性,并且贡献相对于输入不具有动态范围线性度并且影响动态范围修改的部件。 描述了其中可变阻抗特性包括自身变化并由可变电抗分流的有效负电阻的装置。 还描述了其中第二电路是响应于两个端子之间的电流以确定它们之间的电压的双端子网络的装置,并且其中电压通过可变滤波器得到,该可变滤波器用于限制电压或通过 的多个路径,包括过滤器和限制器。

    Compressor and expander circuits having control network responsive to signal level in circuit
    42.
    发明授权
    Compressor and expander circuits having control network responsive to signal level in circuit 失效
    具有控制网络的压缩机和扩展电路响应于电路中的信号电平

    公开(公告)号:US3775705A

    公开(公告)日:1973-11-27

    申请号:US3775705D

    申请日:1972-03-08

    发明人: DOLBY R

    IPC分类号: H03G9/02 H04B1/64

    CPC分类号: H04B1/64 H03G9/025

    摘要: Compressor and expander circuits are constructed by combining the outputs of two circuit paths, both connected to an input terminal. The combining is effected by a variable combining means which responds to a signal level in the circuit to vary the proportions in which the two circuit paths contribute to the output signal.

    摘要翻译: 压缩机和扩展器电路通过组合两个连接到输入端子的两个电路路径的输出而构成。 组合由可变组合装置实现,该可变组合装置响应于电路中的信号电平以改变两个电路路径对输出信号的贡献的比例。

    Wide dynamic range noise masking compandor
    43.
    发明授权
    Wide dynamic range noise masking compandor 失效
    宽动态范围噪音遮蔽计

    公开(公告)号:US3732371A

    公开(公告)日:1973-05-08

    申请号:US3732371D

    申请日:1971-05-10

    申请人: BURWEN RICHARD S

    发明人: BURWEN RICHARD S

    IPC分类号: H03G7/00 H03G9/02 H04B1/64

    CPC分类号: H04B1/64 H03G7/002 H03G9/025

    摘要: A noise masking compandor for greatly reducing the noise added to a wide dynamic range audio signal in passing through a noisy channel, such as a tape recorder. The audio signal, having a dynamic range of approximately 90 db, is compressed to a dynamic range of approximately 30 db for transmission through the noisy channel then subsequently expanded in a complementary fashion to its original 90 db range to provide a faithful reproduction of the original signal without noticeable noise. Compression and expansion result from high precision rectifiers to minimize distortion, and are further achieved without the need for maintaining precisely constant input and output levels for the noisy channel to avoid frequency response distortion. A high degree of high and low frequency signal preemphasis is provided in the compression and expansion characteristic without creating overload problems for the noisy channel.

    摘要翻译: 噪声屏蔽压缩器,用于大大降低通过噪声通道(例如磁带录音机)的宽动态范围音频信号所带来的噪音。 具有大约90db的动态范围的音频信号被压缩到大约30db的动态范围,以便通过噪声信道传输,随后以互补的方式扩展到其原始的90db范围,以提供对原始信号的忠实再现 信号没有明显的噪音。 压缩和扩展来自高精度整流器以最小化失真,并且进一步实现,而不需要为噪声通道保持精确恒定的输入和输出电平以避免频率响应失真。 在压缩和扩展特性中提供了高度的高低频信号预加重,而不会为噪声通道造成过载问题。

    Loudspeaking telephone
    44.
    发明授权
    Loudspeaking telephone 失效
    扬声器电话

    公开(公告)号:US3610835A

    公开(公告)日:1971-10-05

    申请号:US3610835D

    申请日:1970-03-17

    发明人: REID GEORGE PAUL

    IPC分类号: H04M9/10 H04B1/64 H04M1/60

    CPC分类号: H04M9/10

    摘要: A circuit is added to a loudspeaking telephone for preventing the telephone form locking in its receive mode in response to high-amplitude received noise whenever the volume control is adjusted to a high setting. This additional circuit controls a variable impedance device of a receiving channel of the telephone without affecting a variable impedance of a transmitting channel thereof. The circuit increases loss in the receiving channel when the amplitude of translated received noise is greater than the amplitude of translated received noise is greater than the amplitude of translated received speech. The increased loss is switched out of the receiving channel when the amplitude of translated received speech exceeds the amplitude of translated received noise.