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    Volume expansion in response to level of pilot signal
    4.
    发明授权
    Volume expansion in response to level of pilot signal 失效
    响应导频信号电平的音量扩展

    公开(公告)号：US3112461A

    公开(公告)日：1963-11-26

    申请号：US5928660

    申请日：1960-09-29

    Applicant: PHILIPS CORP

    Inventor： DE JAGER FRANK ,  GERWEN PETRUS JOSEPHUS VAN

    IPC: H03G7/02 ,  H04B1/64

    CPC classification number: H03G7/02 ,  H04B1/64

    Abstract: 968,482. Automatic volume control. PHILIPS ELECTRICAL INDUSTRIES Ltd. Sept. 30, 1960, No. 33633/60. Heading H4R. An arrangement for the volume expansion of a band of compressed information signals which is accompanied by an adjacent pilot signal, the pilot signal having an amplitude inversely proportional to the amplitude of the original uncompressed band of information signals, is such that the compressed information signals and pilot signal are applied to a circuit comprising a frequency shift stage which increases the frequency distance between the information signals and pilot signal, both signals being applied to an amplitude limiter to provide a series of pulses, the duration of said pulses being inversely proportional to the amplitude of the pilot signal, filter means being provided for deriving volume expanded information signals at the output of the filter. Incoming carrier signals are received by an aerial (Fig: 1, not shown) and supplied to a mixer stage having a local oscillator which is connected through an intermediate frequency oscillator to a demodulator. Speech signals in the band 0.3 to 3.4 kc./s. and an adjacent pilot signal of frequency 3.7 kc./s. are derived from the output of the demodulator. The speech signals are supplied to a low-pass filter 9 (Fig. 3) having cut-off of 3.4 kc./s. and via transformer 17 to an amplitude limiter. The pilot signal is applied through a filter 10 (3.6 to 3.8 kc./c.) to a ring modulator 18 to which is connected through terminals 19 an oscillator of frequency 20 kc./s. A frequency-converted pilot signal in the band 23.6 to 23.8 kc./s. is selected by filter 20 and, after amplification in amplifier 21 applied to the amplitude limiter. This comprises two rectifiers 23, 24 in the control grid circuit of amplifier 22. The limiting bias of rectifiers 23, 24 is derived from a cathode resistor 25. The limited signals are amplified in amplifier 22 and supplied to low-pass filter 27 having a cut-off frequency of 3.4 kc./8. from where volume expanded information signals are obtained. These are applied to a low frequency amplifier and reproducer (Fig. 1, not shown). In a modification, Fig. 4, the pilot signal, after passing through filter 10, is rectified by stage 29 and passed through a low-pass filter 30 having a cut-off of 100 c/s. Modulator 11,of push-pull type, is constructed for modulation of direct voltages. A variable attenuator 31 provides for adjustment of the upper limit of the expansion control range. The upper limit of the control range may alternatively be effected by providing carrier wave leakage in the modulator 11 or by supplying a constant direct voltage to modulator 11. The pilot signal may be selected in the intermediate frequency band and supplied to the limiter together with the detected speech signals. In such arrangement the frequency shift between pilot signal and speech signals is not effected by frequency conversion of the audio-frequency pilot signal but by directly using the pilot signal in the intermediate frequency band. Specification 968;481 is referred to.

    Device for the transmission of rectangular synchronous information pulses
    6.
    发明授权
    Device for the transmission of rectangular synchronous information pulses 失效
    用于传输矩形同步信息脉冲的设备

    公开(公告)号：US3611143A

    公开(公告)日：1971-10-05

    申请号：US3611143D

    申请日：1969-07-09

    Applicant: PHILIPS CORP

    Inventor： GERWEN PETRUS JOSEPHUS VAN

    IPC: H04L27/04 ,  H03K7/00 ,  H04B1/04

    CPC classification number: H04L27/04

    Abstract: A system for the transmission of rectangular synchronous information pulses from an information source to an information consumer within a prescribed frequency band in which the information pulse is in coincidence with different pulses from a series equidistant clock pulse generator, in which system use is made of a switching modulated device for the direct modulation of rectangular information pulses on to a rectangular carrier oscillator. A band-pass filter and a correction circuit follow the switching modulation device for the suppression of unwanted modulation products generated in the switching modulation device.

    Frequency detector
    9.
    发明授权
    Frequency detector 失效
    频率检测器

    公开(公告)号：US2995707A

    公开(公告)日：1961-08-08

    申请号：US76407358

    申请日：1958-09-29

    Applicant: PHILIPS CORP

    Inventor： DE JAGER FRANK ,  GERWEN PETRUS JOSEPHUS VAN

    IPC: G01R23/00 ,  G01R27/12 ,  G10L25/00

    CPC classification number: G01R27/12 ,  G01R23/00 ,  G10L25/00

    Abstract: 844,561. Frequency discriminators. PHILIPS ELECTRICAL INDUSTRIES Ltd. Oct. 10, 1958 [Oct. 14, 1957], No. 32423/58. Class 40(5). [Also in Group XXXVI] In a frequency detector for the detection of the variation of a characteristic speech frequency situated within a speech sub-band, the speech sub-band, which is selected by means of a filter 4, is supplied to two channels 6, 7 connected in parallel, the channel 6 comprising a differentiating network 8 and a rectifier 9 and the second a rectifier 11, the output voltages from the channel being fed to a ratio meter 13 the output voltage of which is the ratio of the amplitudes of the channel output voltages and a measure of the frequency. Low-pass filters 10 and 12 are included in branches 6, 7 respectively, and, if the input voltage of rectifier 11 is a (t) at a certain instant that to rectifier 9 is #a(t), so that the ratio of the output voltages of filters 10 and 12 is proportional to awdt/adt and therefore to the frequency. In the embodiment shown, the output direct voltages of filters 10, 12 are converted into alternating voltages of frequencies fi f 2 , corresponding in amplitude to the direct voltages, by means of amplitude modulators 15, 16, carrier wave oscillators 17, 18 of frequencies f 1 f 2 and output filters 19, 20, the outputs of the oscillators and filters being connected through attenuators 21, 22 to adjust the strength ratio of the carrierwave oscillations. A ratio meter for use in the detector is shown in Fig. 4. The alternating voltage derived from channel 6 of frequency f 1 and amplitude-modulated by the rectified differentiated input signal is applied to the grid of a pentode 25 through a resistor 23, the alternating voltage derived from channel 7 of frequency f 2 and amplitude modulated by the rectified input signal being applied to the grid through a resistor 26. Slope control is provided for the pentode 25 and the amplitude of oscillations at frequency f 2 at the output of pentode 25 is therefore kept constant, so that the slope of the pentode 25 varies inversely as the amplitude of the input voltage at frequency f 2 . The voltage at frequency fi is selected by a filter 30 and rectified, the output at 38, 39 being a direct voltage proportional to the amplitude ratio between the output voltages of channels 6 and 7. In the embodiment of Fig. 5, the ratio is determined by amplitude limitation instead of slope control. An amplitude limiter comprising rectifiers 45, 46 has an output consisting of a voltage of frequency f 2 modulated by the voltage of frequency f 1 the frequency deviation of said f.m. voltage being proportional to f 1 : f 2 , the amplitude of f 1

    Transmission system and associated transmitters and receivers for the transmission of synchronous pulse signals
    10.
    发明授权
    Transmission system and associated transmitters and receivers for the transmission of synchronous pulse signals 失效
    传输系统和相关的发射机和接收机传输同步脉冲信号

    公开(公告)号：US3701852A

    公开(公告)日：1972-10-31

    申请号：US3701852D

    申请日：1971-08-23

    Applicant: PHILIPS CORP

    Inventor： SLUIJTER ROBERT JOHANNES ,  GERWEN PETRUS JOSEPHUS VAN

    IPC: H04L25/49 ,  H04L27/02 ,  H04B1/00

    CPC classification number: H04L27/02 ,  H04L25/4925

    Abstract: A transmission system for the transmission of binary synchronous pulse signals in the base group of a carrier telephony system in which these pulse signals are converted into two separate pulse signals, at half the original information speed each, which separate pulse signals are each modulated in accordance with a single sideband method on carrier signals of different frequencies located on either side of the central portion of the transmission band (base group) so that the transmitted frequency spectrum is constituted by the two non-adjacent single sideband signals.

    Abstract translation: 一种用于在载波电话系统的基组中传输二进制同步脉冲信号的传输系统，其中这些脉冲信号被转换成两个单独的脉冲信号，每个单独的脉冲信号以原始信息速度的一半分开，每个脉冲信号根据 对于位于传输频带（基组）的中心部分的任一侧的不同频率的载波信号，使用单边带方法，使得发送的频谱由两个不相邻的单边带信号构成。

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