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公开(公告)号：US06870934B2
公开(公告)日：2005-03-22
申请号：US10195206
申请日：2002-07-15
CPC分类号： H04R29/001 , G01R31/2825 , H04R2420/05
摘要： The presence or absence of a speaker connected to an output terminal of an audio system is determined based on the electro-generator properties of the speaker. The audio system includes an output amplifier coupled to the output terminal. The method includes driving the output amplifier with a predetermined drive signal sufficient to produce a predetermined speaker excursion if a speaker is connected to the output terminal. The output amplifier is then isolated from the output terminal. A signal at the output terminal is sensed after the output amplifier is isolated. The sensed signal is compared with a predetermined reference for determining whether a speaker back-EMF is present. A speaker detection signal is generated indicating absence of a speaker if the back-EMF is not present.
摘要翻译： 连接到音频系统的输出端子的扬声器的存在或不存在基于扬声器的发电机特性来确定。 音频系统包括耦合到输出端的输出放大器。 该方法包括：如果扬声器连接到输出端，驱动具有足以产生预定扬声器偏移的预定驱动信号的输出放大器。 然后输出放大器与输出端子隔离。 在输出放大器隔离之后，检测输出端子处的信号。 将感测到的信号与用于确定扬声器反电动势是否存在的预定参考进行比较。 如果不存在反电动势，则产生指示扬声器不存在的扬声器检测信号。
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公开(公告)号：US06577737B1
公开(公告)日：2003-06-10
申请号：US09506295
申请日：2000-02-17
IPC分类号： H03G1100
摘要： A method of detecting a DC offset in an audio signal provided by an audio processing unit to an audio power amplifier, wherein the audio amplifier provides a clip detect signal back to the audio processing unit, wherein the method comprises the steps of sampling the clip detect signal to determine if the clip detect is active. Detecting a power level of the audio amplifier if the clip detect is active. Next, comparing the power level to a predetermined power threshold. Then, identifying a dc offset if the power level is less than the predetermined power threshold.
摘要翻译： 一种检测由音频处理单元提供给音频功率放大器的音频信号中的DC偏移的方法，其中音频放大器向音频处理单元提供一个片段检测信号，其中该方法包括以下步骤：对片段检测进行采样 信号以确定剪辑检测是否活动。 如果剪辑检测有效，则检测音频放大器的功率电平。 接下来，将功率电平与预定功率阈值进行比较。 然后，如果功率电平小于预定功率阈值，则识别直流偏移。
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公开(公告)号：US5357574A
公开(公告)日：1994-10-18
申请号：US990143
申请日：1992-12-14
申请人： John E. Whitecar
发明人： John E. Whitecar
CPC分类号： H04H20/48 , H03D1/22 , H04B1/1653
摘要： A digital radio receiver generates coherent signals for synchronous detection without use of a phase-locked loop by employing an adaptive notch filter to cancel the desired signal. The cancelling signal is employed as the coherent signal for synchronous detection. The invention obtains faster locking to the desired signal, a wider capture range, and more efficient software coding in a digital signal processing receiver.
摘要翻译： 数字无线电接收机通过采用自适应陷波滤波器来消除所需信号，产生用于同步检测的相干信号，而不使用锁相环。 采用消除信号作为同步检测的相干信号。 本发明在数字信号处理接收机中获得更快的锁定到期望的信号，更宽的捕获范围和更有效的软件编码。
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4.发明授权Composite signal generation and decoding in digital signal processing automotive audio system 失效数字信号处理汽车音响系统中的复合信号发生与解码
公开(公告)号：US5327132A
公开(公告)日：1994-07-05
申请号：US980070
申请日：1992-11-23
CPC分类号： H04B1/1646
摘要： A digital signal processing automotive audio system uses an analog audio source providing stereo output signals. One of the stereo signals is mixed to a distinct frequency band and summed with the other stereo signal to form a composite signal which can be digitized in a single analog-to-digital converter. Separate digital stereo signals are recovered using digital signal processing.
摘要翻译： 数字信号处理汽车音响系统使用提供立体声输出信号的模拟音频源。 其中一个立体声信号被混合到不同的频带，并与另一个立体声信号相加以形成可以在单个模数转换器中数字化的复合信号。 使用数字信号处理来恢复单独的数字立体声信号。
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公开(公告)号：US5467399A
公开(公告)日：1995-11-14
申请号：US298703
申请日：1994-08-31
申请人： John E. Whitecar
发明人： John E. Whitecar
CPC分类号： H04H20/48 , H03D1/22 , H04B1/1653
摘要： A digital radio receiver generates coherent signals for synchronous detection without use of a phase-locked loop by employing an adaptive notch filter to cancel the desired signal. The cancelling signal is employed as the coherent signal for synchronous detection. The invention obtains faster locking to the desired signal, a wider capture range, and more efficient software coding in a digital signal processing receiver.
摘要翻译： 数字无线电接收机通过采用自适应陷波滤波器来消除所需信号，产生用于同步检测的相干信号，而不使用锁相环。 采用消除信号作为同步检测的相干信号。 本发明在数字信号处理接收机中获得对期望信号的更快的锁定，更宽的捕获范围和更有效的软件编码。
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公开(公告)号：US5450624A
公开(公告)日：1995-09-12
申请号：US1688
申请日：1993-01-07
CPC分类号： H04R29/001 , H04B17/20 , H04R5/04 , G01R31/041 , G01R31/2825 , H04R2420/05
摘要： A method and apparatus for determining the connection status of a communication system speaker connection to the amplifier includes digital signal processing (DSP) circuitry contained in the system receiving a clip detect feedback loop from the amplifier in response to a tone signal delivered to the amplifier from the DSP microprocessor. Preferably, the diagnosis is initiated by actuation of a predetermined plurality of controllers on a face control unit, each of which is otherwise actuated individually to control portions of the communication system. Preferably, a tone signal generated for diagnosis is generally inaudible to the human ear but the front control unit includes a display screen for illustrating the condition of the speaker-to-amplifier connection after the diagnostic function has been completed.
摘要翻译： 用于确定与放大器的通信系统扬声器连接的连接状态的方法和装置包括系统中包含的数字信号处理（DSP）电路，其响应从传送到放大器的音调信号接收来自放大器的片段检测反馈环路 DSP微处理器。 优选地，通过致动面部控制单元上的预定多个控制器来启动诊断，每个控制单元另外被单独地致动以控制通信系统的部分。 优选地，生成用于诊断的音调信号通常对人耳听不到，但前控制单元包括用于说明诊断功能完成之后的扬声器与放大器连接的状态的显示屏幕。
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公开(公告)号：US5400188A
公开(公告)日：1995-03-21
申请号：US162548
申请日：1993-12-06
IPC分类号： G11B15/087 , G11B27/22 , G11B5/09
CPC分类号： G11B27/22 , G11B15/087
摘要： Digital signal processing (DSP) employing a differential mean calculation automatically distinguishes sections of blank tape from program material (such as music or voice) on cassette tapes. Blank tape produces a negligible differential mean value while program material produces substantial differential mean values. Thus, each differential mean is compared to a threshold so that a cassette player can be commanded to fast forward through a blank section of tape. A music envelope detector insures that low amplitude music signals are not detected as blank.
摘要翻译： 使用差分均值计算的数字信号处理（DSP）会自动区分空白磁带的部分与录像带上的节目素材（如音乐或声音）。 空白胶带产生可忽略的微分平均值，而程序材料产生实质的差分均值。 因此，将每个差分均值与阈值进行比较，使得可以命令盒式播放器快速前进通过磁带的空白部分。 音乐包络检测器确保低振幅音乐信号不被检测为空白。
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8.发明授权Apparatus and method for IF switching in a dual-tuner, dual-IF, HD radio and FM/AM radio receiver 有权双调谐器，双中频，高清无线电和FM / AM无线电接收机中的IF切换的装置和方法公开(公告)号：US07466959B2
公开(公告)日：2008-12-16
申请号：US11171613
申请日：2005-06-30
申请人： Robert G. DeMoor , John E. Whitecar
发明人： Robert G. DeMoor , John E. Whitecar
IPC分类号： H04B1/68
CPC分类号： H04B1/1027
摘要： In a dual-channel HD radio receiver, when the broadband filter channel is compromised, the broadband channel is inactivated and the narrowband channel is activated. By mixing the signals of the two channels during the change, undesirable audio artifacts can be minimized.
摘要翻译： 在双通道HD无线电接收机中，当宽带滤波器信道受到损害时，宽带信道被去激活，并且窄带信道被激活。 通过在改变期间混合两个通道的信号，可以使不期望的音频伪影最小化。
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公开(公告)号：US07202731B2
公开(公告)日：2007-04-10
申请号：US11155800
申请日：2005-06-17
IPC分类号： G01R19/00
CPC分类号： H03F1/3264 , H03G3/301
摘要： A system and method for predicting and limiting distortion of an amplified signal is described. The system includes a variable total harmonic distortion (“THD”) clipping predictor, a comparator in communication with the variable THD clipping predictor and a distortion limiter in communication with the comparator. As for the method, a reference power supply value, a maximum desired total harmonic distortion value and a preamplified signal value is provided. A THD output threshold value is calculated based on the reference power supply value and the maximum desired THD value and is then compared to the preamplified signal value. Depending on if the preamplified signal value is greater than or less than the THD output threshold value, the amplitude of the preamplified signal may be increased or decreased.
摘要翻译： 描述了用于预测和限制放大信号的失真的系统和方法。 该系统包括可变总谐波失真（“THD”）限幅预测器，与可变THD限幅预测器通信的比较器和与比较器通信的失真限制器。 对于该方法，提供参考电源值，最大期望总谐波失真值和预放大信号值。 基于参考电源值和最大期望THD值计算THD输出阈值，然后将其与前置放大信号值进行比较。 根据预放大信号值是否大于或小于THD输出阈值，可以增大或减小前置放大信号的幅度。
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公开(公告)号：US5465406A
公开(公告)日：1995-11-07
申请号：US300894
申请日：1994-09-06
CPC分类号： H03G3/3052
摘要： A digital radio receiver avoids overshoot or undershoot of an AGC control loop by isolating a carrier signal using an adaptive narrow bandpass filter. The carrier strength signal is used to control either a full AGC loop or an AGC overshoot limiter to avoid sudden changes in the audio output level.
摘要翻译： 数字无线电接收机通过使用自适应窄带通滤波器隔离载波信号来避免AGC控制环路的过冲或下冲。 载波强度信号用于控制完整的AGC环路或AGC过冲限幅器，以避免音频输出电平的突然变化。
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