| 摘要 |
A phase control apparatus for a video cassette recorder comprising a control head for reproducing a control signal recorded on a control track of a tape, a control signal amplification circuit for amplifying the reproduced control signal at a varied amplification gain, a control signal wave-shaping circuit for wave-shaping an output signal from the control signal amplification circuit and stabilizing the wave-shaped signal, an amplification gain control circuit for controlling the amplification gain of the control signal amplification circuit in response to an output signal from the control signal wave-shaping circuit, a phase control circuit for detecting an phase error and a rotation speed of a capstan motor in response to the output signal from the control signal wave-shaping circuit and an output frequency from the capstan motor and outputting phase and speed detect signals in accordance with the detected results, and a capstan motor driving circuit for driving the capstan motor in response to the phase and speed detect signals to correct the phase error of the capstan motor. The amplification gain control circuit is provided with a microprocessor for outputting an amplification gain control signal and an amplification gain variation circuit for varying the amplification gain in response to the amplification gain control signal.
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