| 摘要 |
PURPOSE:To output only a required pulse even if any kind of noise is mixed to an input signal by combining a clamp circuit and a Schmitt circuit. CONSTITUTION:The clamped signal is inputted to the Schmitt circuit comprising transistors (TRs) 23, 25 and resistors 21, 22, 24, 26, 27, and the TR25 is turned on at the leading edge of a signal, then a base potential of the TR23 is decreased and the TR23 is turned off and the potential of the TR25 is increased further. When the signal is decreased, the base potential of the TR25 is decreased, and when the TR25 is turned off, the base of the TR23 is increased and the TR23 is turned on. Thus, the base potential of the TR25 is decreased further. The Schmitt circuit is constituted by giving a hysteresis characteristic to the base of the TR25 so as to prevent chattering to noise. Then the signal obtained from the collector of the TR25 is outputted (13) by inverting it at a TR30. |
