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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
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。
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公开(公告)号：US4306201A
公开(公告)日：1981-12-15
申请号：US77179
申请日：1979-09-20
申请人： Shoichi Nakamura
发明人： Shoichi Nakamura
摘要： A signal processing circuit for improving the signal-to-noise ratio of input signals, such as audio signals recorded on tape, has a low-pass filter circuit for controllably filtering signals at the lower end of the frequency spectrum, and a high-pass filter circuit for controllably filtering signals at the higher end of the frequency spectrum, with the high-pass filter circuit and the low-pass filter circuit defining the only paths through the signal processing circuit for the input signals. Associated control circuitry provides first and second control signals to control the attenuation of signals at the lower-frequency and higher-frequency parts of the spectrum, respectively, in dependence on the amplitude of the input signals in the respective parts of the spectrum. Preferably, the controllable low-pass and high-pass filter circuits are connected in parallel between input and output terminals, a low-frequency band control unit is provided to control the amount of attenuation of the low-pass filter circuit and a high-frequency band control unit is provided to control the cut-off frequency of the high-pass filter circuit. In one practical arrangement for recording audio signals, signals taken from the output terminal of the signal processing circuit are recorded on tape. For playing back these recorded signals, the input and output terminals of the processing circuit are respectively connected to the output terminal and negative feedback input of an operational amplifier.
摘要翻译： 用于提高诸如记录在磁带上的音频信号的输入信号的信噪比的信号处理电路具有用于可控地滤波在频谱下端的信号的低通滤波器电路，以及高通 滤波器电路，用于可控地对频谱的较高端的信号进行滤波，高通滤波器电路和低通滤波器电路通过信号处理电路为输入信号定义唯一的路径。 相关控制电路提供第一和第二控制信号，以分别根据频谱各部分中的输入信号的幅度来控制频谱的较低频和高频部分的信号的衰减。 优选地，可控低通滤波器和高通滤波器电路并联连接在输入和输出端子之间，提供低频带控制单元以控制低通滤波器电路的衰减量和高频 提供频带控制单元以控制高通滤波器电路的截止频率。 在用于记录音频信号的一个实际布置中，从信号处理电路的输出端取出的信号被记录在磁带上。 为了回放这些记录的信号，处理电路的输入和输出端分别连接到运算放大器的输出端和负反馈输入。
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公开(公告)号：US4250471A
公开(公告)日：1981-02-10
申请号：US901421
申请日：1978-05-01
申请人： Michael G. Duncan
发明人： Michael G. Duncan
摘要： This invention discloses new and unique detectors suitable for controlling any device needing precise conversion of AC voltage to an equivalent DC voltage. The detector may also be used as an excellent non-linear low pass filter. More particularly, the detector is suitable for controlling meter movements and the variable gain amplifiers which are used in compressors, expanders, compandors, limiters and other noise reduction systems, The detectors control gain such that unnecessary gain changes are eliminated, overshoot transient distortion is minimized, distortion due to ripple is minimized, and pumping is eliminated. As described herein, the detector uses two interacting memories to provide a output signal from the detector which can be used to drive a variable gain amplifier for achieving optimum characteristics of a compressor, expandor or compandor. This is achieved by using inter-connecting circuitry between the two memories and between the inputs and outputs of the detector such that one of the memories dominates and controls the output signal for most input voltage situations, but in the event of drastic input signal changes the second memory interreacts with the first memory.
摘要翻译： 本发明公开了适用于控制任何需要将AC电压精确转换成等效直流电压的装置的新型和独特的检测器。 检测器也可以用作优异的非线性低通滤波器。 更具体地，检测器适用于控制仪表运动和用于压缩机，扩展器，压缩器，限制器和其它降噪系统的可变增益放大器。检测器控制增益，使消除不必要的增益变化，使过冲瞬变失真最小化 ，由于波纹引起的失真被最小化，并且消除了泵浦。 如本文所述，检测器使用两个相互作用的存储器来提供来自检测器的输出信号，其可以用于驱动可变增益放大器以实现压缩机，扩展器或压缩器的最佳特性。 这是通过使用两个存储器之间以及检测器的输入和输出之间的互连电路来实现的，使得存储器中的一个支配并控制大多数输入电压情况下的输出信号，但是在剧烈的输入信号改变的情况下 第二个内存与第一个内存相互影响。
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公开(公告)号：US4220875A
公开(公告)日：1980-09-02
申请号：US774003
申请日：1977-07-22
申请人： Rodney J. Lawton
发明人： Rodney J. Lawton
CPC分类号： H03H11/46 , H03G1/0035 , H03H11/24 , H03H11/48
摘要： This disclosure relates to an electronic circuit which has a controllable impedance. This type of circuit is well suited for application in noise suppression circuits or in signal compression/expansion circuits. The circuit has two stages. The first stage is a voltage to current converter. The second stage is a variable gain current amplifier. The output of the second stage is connected by a feedback loop to an input of the first stage. The circuit has a variable impedance which can be controlled by an external signal. The imput impedance of the circuit is linearly related to the applied control signal.
摘要翻译： 本公开涉及具有可控阻抗的电子电路。 这种电路非常适用于噪声抑制电路或信号压缩/扩展电路。 电路有两个阶段。 第一级是电压到电流转换器。 第二级是可变增益电流放大器。 第二级的输出通过反馈回路连接到第一级的输入端。 该电路具有可由外部信号控制的可变阻抗。 电路的输入阻抗与所施加的控制信号线性相关。
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35.发明授权Circuit arrangement for the selective compression or expansion of the dynamic range of a signal 失效用于选择性压缩或扩展信号动态范围的电路布置
公开(公告)号：US4190806A
公开(公告)日：1980-02-26
申请号：US943978
申请日：1978-09-20
申请人： Jurgen Wermuth
发明人： Jurgen Wermuth
摘要： A compander system is described, in which the `compression` and `expansion` modes are established by the selective use of a compression or expansion circuit as such or as a negative feed-back branch for a back-coupled amplifier.
摘要翻译： 描述了压缩扩展系统，其中通过选择性地使用压缩或扩展电路或者用于背耦合放大器的负反馈分支来建立“压缩”和“扩展”模式。
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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
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。
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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
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。
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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
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。
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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
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。
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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
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。
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