AFT CIRCUIT
    2.
    发明授权
    AFT CIRCUIT 失效
    AFT电路

    公开(公告)号:US4207597A

    公开(公告)日:1980-06-10

    申请号:US95551678

    申请日:1978-10-30

    Applicant: RCA CORP

    CPC classification number: H03J7/04 H03D3/26 H03L7/02

    Abstract: An automatic fine tuning (AFT) circuit is provided which generates an AFT control signal in response to a video intermedate frequency (I.F.) signal. The I.F. signal is supplied to the input of a current source amplifier, which provides current signals of like phase relationship to a discriminator network. The discriminator network is comprised of two tuned circuits, one of which is resonant at a frequency below the desired frequency of the I.F. picture carrier, and the other resonant at a frequency above the desired frequency. The tuned circuits develop voltage variations which vary differentially in magnitude in response to the frequency deviation of the I.F. picture carrier from its desired frequency. The differentially related voltages are detected by two peak detector networks for use as AFT control signals. The current source amplifier and peak detector networks may be conveniently fabricated on a single I.C. chip. The tuned circuits are coupled to the current source amplifier and peak detector networks through two external I.C. terminals.

    Abstract translation: 提供了一种自动微调(AFT)电路,其响应于视频中间频率(I.F.)信号产生AFT控制信号。 I.F. 信号被提供给电流源放大器的输入,电流源放大器向鉴别器网络提供类似相位关系的电流信号。 鉴别器网络由两个调谐电路组成,其中一个调谐电路以低于I.F的期望频率的频率谐振。 图像载体,另一个以高于期望频率的频率谐振。 调谐电路产生响应于I.F.的频率偏差而在幅度上差异变化的电压变化。 图片载体从其所需的频率。 差分相关电压由两个峰值检测器网络检测,用作AFT控制信号。 电流源放大器和峰值检测器网络可以方便地在单个I C上制造。 芯片。 调谐电路通过两个外部I C耦合到电流源放大器和峰值检测器网络。 终端。

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