公开(公告)号：US4309676A

公开(公告)日：1982-01-05

申请号：US185892

申请日：1980-09-10

申请人： Hubert Martin ,  Gerald W. Beene

发明人： Hubert Martin ,  Gerald W. Beene

IPC分类号： H03G7/00 ,  H04B1/64

CPC分类号： H03G7/001 ,  H04B1/64

摘要： An instantaneous compressor and an instantaneous expandor both of which use the logarithmic characteristics of diodes to provide compression and expansion, respectively, of uncompressed analog PAM signals and compressed analog PAM signals. Both the compressor and expandor also include circuitry having a temperature dependent gain characteristic. The signal at the compressor output is a temperature independent compressed analog signal which follows the compressor's logarithmic encoding characteristic. The signal at the output of the expandor is a temperature independent uncompressed analog signal which is substantially identical to the analog signal at the compressor input.

摘要翻译： 瞬时压缩机和瞬时膨胀器都使用二极管的对数特性分别提供未压缩模拟PAM信号和压缩模拟PAM信号的压缩和扩展。 压缩机和膨胀器都包括具有温度依赖增益特性的电路。 压缩机输出端的信号是一个温度无关的压缩模拟信号，跟随压缩机的对数编码特性。 扩展器输出端的信号是与压缩机输入端的模拟信号基本相同的独立于温度的未压缩模拟信号。

公开(公告)号：US4110699A

公开(公告)日：1978-08-29

申请号：US670505

申请日：1976-03-25

申请人： Charles W. Bethards

发明人： Charles W. Bethards

IPC分类号： H03C1/02 ,  H03G3/30 ,  H03G7/00 ,  H04B1/04 ,  H04B1/64 ,  H03B3/02 ,  H03K1/14

CPC分类号： H03G7/004 ,  H04B1/64 ,  H04B2001/0408

摘要： An amplitude modulated transmitter includes an audio amplifier which, via a radio frequency (RF) power supply modulator, modulates an RF amplifier and carrier. Fluctuations in the direct current DC bias to the RF amp, such as are common in mobile applications, vary the modulation index of the transmitted signal.To minimize DC bias affects on the modulation index, the invention contemplates an audio compressor which senses both audio signal level and DC bias level and, in response thereto, controls audio signal compression to maintain the desired percent modulation. Compression is effected by changing the bias on a semiconductor device which, in turn, attenuates audio signals at the input of a fixed gain audio amplifier. A feedback path around the audio amplifier senses both DC voltage and audio signal level and produces an appropriate control signal to bias the semiconductor device, thereby altering audio compression.

摘要翻译： 幅度调制发射机包括经由射频（RF）电源调制器调制RF放大器和载波的音频放大器。 在RF放大器的直流DC偏置中的波动，例如在移动应用中是常见的，改变了发射信号的调制指数。

公开(公告)号：US4068139A

公开(公告)日：1978-01-10

申请号：US710958

申请日：1976-08-09

申请人： Derek Bray

发明人： Derek Bray

IPC分类号： H03G1/00 ,  H03G9/18 ,  H04B1/64 ,  H03G7/06 ,  H03K1/14

CPC分类号： H04B1/64 ,  H03G1/0035 ,  H03G9/18

摘要： A current variable shunt impedance with a non-linear control characteristic intended to functionally imitate and replace a field effect transistor responsive to a control voltage applied to its gate electrode having a source-drain path connected as a variable impedance shunt resistor in the variable frequency high pass filter section of the commercially popular Dolby B noise reduction system. The invention allows a large part of the Dolby B encode decode circuitry to be embodied in low-cost integrated circuit form while maintaining performance characteristics which closely match existing standards. These standards were previously established using noise reduction systems fabricated from discrete circuit components. The complementary nature of the encode and decode operations used to process a signal makes such matching of performance characteristics to the established standards critical.

摘要翻译： 具有非线性控制特性的电流可变分流阻抗，其功能上模拟和替换场效应晶体管，所述场效应晶体管响应于施加到其栅电极的控制电压，其源极 - 漏极路径以可变频率高度连接为可变阻抗并联电阻器 商业流行的杜比B降噪系统的通过滤波器部分。 本发明允许大部分杜比B编码解码电路以低成本集成电路形式实现，同时保持与现有标准紧密匹配的性能特征。 以前使用由分立电路组件制造的降噪系统建立了这些标准。 用于处理信号的编码和解码操作的互补性质使得性能特征与已建立标准的匹配成为关键。

公开(公告)号：US3969680A

公开(公告)日：1976-07-13

申请号：US543931

申请日：1975-01-24

申请人： Jurgen Wermuth

发明人： Jurgen Wermuth

IPC分类号： G11B20/04 ,  H03G3/20 ,  H03G7/00 ,  H03G9/02 ,  H03G9/18 ,  H04B1/64

CPC分类号： H03G3/301 ,  H03G7/004 ,  H03G9/025 ,  H03G9/18 ,  H04B1/64

摘要： In a circuit for the automatic dynamic compression or expansion of a signal between its input and its output, the circuit presenting a useful signal path connected between its input and its output and containing a setting member which is electronically controllable for varying the transmission factor between the circuit input and output, the circuit also presenting a branch path connected at one point to the useful signal path and containing a control voltage generator for generating, from the signal in the useful signal path, a control voltage applied to control the setting member, there is also provided a second setting member connected in the branch path and arranged to be electronically controllable for varying the transmission factor exhibited by the branch path, and means connecting the output of the control voltage generator to the second setting member for effecting a counterregulation of the transmission factor of the branch path, relative to the transmission factor variation imparted to the useful signal path.

摘要翻译： 在用于在其输入和输出之间自动动态压缩或扩展信号的电路中，该电路呈现连接在其输入端与其输出端之间的有用信号路径，并且包含可电子控制的设定元件，用于改变 电路输入和输出，电路还呈现分支路径，其一端连接到有用信号路径并且包含控制电压发生器，用于从有用信号路径中的信号产生用于控制设定构件的控制电压，那里 还设置有连接在分支路径中的第二设置构件，并且被布置为可电子控制以改变由分支路径显示的传输因素，以及将控制电压发生器的输出连接到第二设置构件的装置，以实现对 分支路径的传输因子相对于传输因子变化 赋予有用的信号路径。

公开(公告)号：US3967219A

公开(公告)日：1976-06-29

申请号：US509076

申请日：1974-09-25

申请人： Ray Milton Dolby

发明人： Ray Milton Dolby

IPC分类号： H03G9/02 ,  H04B1/64 ,  H03G11/04 ,  H03H7/10 ,  H03H7/16

CPC分类号： H04B1/64 ,  H03G9/025

摘要： A compressor or expander circuit is constructed by connecting a plurality of impedance networks in series across input terminals, at least one network being frequency selective. Output terminals are connected across one or more of the networks. The frequency selective network varies its parameters in response to the level of components within a restricted frequency band determined by this network so as to narrow the band when the level of such components increases. This includes such components from the restricted band and thereby from the compression or expansion action.

摘要翻译： 压缩机或扩展器电路通过串联连接跨输入端子的多个阻抗网络构成，至少一个网络是频率选择的。 输出端子连接在一个或多个网络上。 频率选择网络响应于由该网络确定的受限频带内的组件的电平而改变其参数，以便当这些组件的级别增加时，使频带变窄。 这包括来自限制带的这些组件，从而由压缩或膨胀动作。

公开(公告)号：US3934190A

公开(公告)日：1976-01-20

申请号：US519631

申请日：1974-10-31

申请人： Ray Milton Dolby

发明人： Ray Milton Dolby

IPC分类号： H03G9/02 ,  H04B1/64

CPC分类号： H03G9/025 ,  H04B1/64

摘要： Compressors and expanders for effecting dynamic range modification are constructed by connecting reactive networks in series for voltage dividing action or in parallel for current dividing action. The output signal is derived from the voltage across or current through one of the networks which includes a series or parallel variable resistance. The variable resistance is controlled in dependence upon the voltage thereacross in the sense required to achieve compression or expansion, as the case may be. The resistance change shifts a turnover frequency of the circuit so as to exclude large amplitude components from the amplitude increase or reduction which is applied to low level components within a restricted frequency band to create the compressor or expander action.

摘要翻译： 用于实现动态范围修改的压缩机和扩展器通过连接用于分压动作的串联的无功电网或并联用于当前分流动作来构建。 输出信号源自包含串联或并联可变电阻的网络之一或电流的电压。 根据情况可以根据实现压缩或膨胀所需的意义上的电压来控制可变电阻。 电阻变化使电路的周转频率偏移，以便从施加到受限频带内的低电平分量的幅度增大或减小中排除大幅度分量，以产生压缩机或扩展器动作。

公开(公告)号：US3775705A

公开(公告)日：1973-11-27

申请号：US3775705D

申请日：1972-03-08

申请人： DOLBY LABORATORIES INC

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。

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。

公开(公告)号：US3500206A

公开(公告)日：1970-03-10

申请号：US3500206D

申请日：1967-03-01

申请人： NIPPON ELECTRIC CO

发明人： KANEKO HISASHI ,  TOMOZAWA ATSUSHI

IPC分类号： H03C3/06 ,  H04B1/64 ,  H04B14/00 ,  H04B1/62

CPC分类号： H04B1/64 ,  H03C3/06 ,  H04B14/006

公开(公告)号：US3482051A

公开(公告)日：1969-12-02

申请号：US3482051D

申请日：1965-12-08

申请人： INT STANDARD ELECTRIC CORP

发明人： BAADE OTTO ,  GASSER LORENZ

IPC分类号： B21C37/04 ,  H04B1/64 ,  H04Q3/00 ,  H04M3/42

CPC分类号： B21C37/047 ,  H04B1/64 ,  H04Q3/00 ,  H04Q3/0012