Sine-wave modulator and playback/recording modulator-demodulator for a
high-fidelity video playback/recording system
    1.
    发明授权
    Sine-wave modulator and playback/recording modulator-demodulator for a high-fidelity video playback/recording system 失效
    用于高保真视频播放/录制系统的正弦波调制器和播放/记录调制解调器

    公开(公告)号:US5715353A

    公开(公告)日:1998-02-03

    申请号:US656443

    申请日:1996-05-31

    摘要: A playback/recording modulating-demodulating device, having a voltage-controlled oscillator (VCO), a voltage-current inverter (VCI), a band-pass filter, an amplitude limiter, and a phase-locked loop. In playback mode, the playback input signal is applied to the band-pass filter, the phase-locked loop is activated, and the VCI is set to produce a reference signal which controls the band-pass filter to tune the playback input signal. The tuned playback signal is applied to the amplitude limiter which produces an amplitude-limited signal which is applied to the phase-locked loop to produce a demodulated playback output signal. In record mode, the phase-locked loop is deactivated, the VCO produces a signal having a frequency which varies according to the voltage of a record input signal, and the VCI outputs a current control signal, having an output current related to the voltage of the record input signal, which is applied to the band-pass filter to control its bandwidth. A signal having a frequency value determined by the voltage of the record input signal is output by the VCO and applied to the band-pass filter, which outputs a record output signal. Thus, in the record mode, the bandwidth of the band-pass filter is related to the frequency of the signal which it filters.

    摘要翻译: 具有压控振荡器(VCO),电压 - 电流逆变器(VCI),带通滤波器,限幅器和锁相环的重放/记录调制解调装置。 在回放模式中,重放输入信号被施加到带通滤波器,锁相环被激活,并且VCI被设置为产生控制带通滤波器的参考信号来调谐播放输入信号。 调谐回放信号被施加到幅度限制器,其产生施加到锁相环的振幅限制信号以产生解调的重放输出信号。 在记录模式下,锁相环被去激活,VCO产生具有根据记录输入信号的电压而变化的频率的信号,并且VCI输出电流控制信号,该电流控制信号具有与 记录输入信号,其被施加到带通滤波器以控制其带宽。 具有由记录输入信号的电压确定的频率值的信号由VCO输出并施加到输出记录输出信号的带通滤波器。 因此,在记录模式中,带通滤波器的带宽与其滤波的信号的频率有关。