| 摘要 |
PURPOSE:To improve the margin of detection against noise, by decreasing a threshold voltage in the amplitude detection of a waveform where the amplitude is decreased. CONSTITUTION:The circuit consists of a circuit which discriminates whether or not the detected amplitude just before the detection of amplitude is before a prescribed time and decreases the threshold voltage through the discrimination and a circuit restoring the decreased threshold voltage. An output pulse width of a one-shot multivibrator circuit 5 is set slightly larger than a minimum magnetization inverting interval. Then, it is when no inversion of magnetization exists that a signal (g) goes to a high level. Thus, the margin of detection of a 3-consecutive magnetization inverted pattern to the center of amplitude is improved by decreasing the threshold voltage K with a signal ANDing the signal (g) and an amplitude detecting signal (e). In this way, the margin of detection against noise is improved. |
