| 摘要 |
PURPOSE:To insure signals against being affected by a noise component overlapping with a character signal by sampling the character signal by a clock pulse synchronizing with a bit synchronizing pulse. CONSTITUTION:By releasing a gate as long as a gate pulse (b) is given, a gate circuit 2 takes out the bit synchronizing pulse (c) from the character signal (a). Given with the bit synchronizing pulse (c), an oscillator circuit 3 outputs a clock pulse at 5.7272 mHz synchronizing with the bit synchronizing pulse (c). Given with a clock pulse (d), a data gate pulse generator circuit 4 outputs a gate pulse (g). Since an analog switch 1 becomes conductive as long as the gate pulse (g) is given, the character signal is sampled. The sampled character signal (h) is compared with a slice voltage V2 set to half the peak of the character signal. As a result a pulse signal (i) is outputted from a comparator 7. Thus noise hardly affects a comparison output signal.
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