| 摘要 |
PURPOSE:To delete the undesired signals and mispulses caused by a saddle and to attain a reproducing action with high reliability, by actuating a 1-shot multivibrator circuit only when the voltage of a data detection signal exceeds a fixed level. CONSTITUTION:The data recorded to a recording medium 1 are detected by a magnetic head 2 and supplied to a filter 5 via a switch circuit 3 and an amplifier circuit 4. The output of the filter 5 is branched into two parts, and one of these two outputs is supplied to a differential amplifier circuit 6. While the other output is supplied to a mobile control circuit 30 which produces an output only when the output of the filter 5 exceeds a fixed level. The outut of the circuit 6 is supplied to a 1-shot multivibrator 8A through a zero cross detecting circuit 7. The output of the circuit 30 is supplied to a clear terminal of the vibrator 8A, and the vibrator 8 can be active only when it receives the output of the circuit 30. The output of the vibrator 8A starts a pulse width setting circuit 15 and produces a reproduction output through an output circuit 10A. Thus the undesired signals are eliminated and the reliability is improved with a reproducing action. |
