| 摘要 |
<p>PURPOSE:To ensure a desired searching speed, by detecting the frequency of the reproduced control signal and using the comparison output between the detection output corresponding to the frequency of the control signal and the variable reference signal for the drive signal. CONSTITUTION:The control signal of a magnetic tape is reproduced by a control head 10 of VTR, and the outputs of positive and negative differential waveforms are applied to a mono-multi 13 of a frequency discriminating circuit 15 through an amplifier 11 and a waveform shaping circuit. The output of the mono-multi 13 is supplied to an integrator 14 to deliver the detection output V4. The output V4 is compared with the reference voltage Vr at a comparator 9, and the difference output Vr-V4=V3 is supplied to a motor drive circuit 5 of a reel motor 4 via a mode change-over switch 6. In this way, a desired searching speed is obtained.</p> |
