| 摘要 |
PURPOSE:To assuredly detect a pulse is case the rise and fall of the pulse are gentle or when the number of pulses must be detected from the zero level, by securing the detection even for such pulse that has a delicate change at a level approximate to the threshold value for the detection of pulse. CONSTITUTION:The input signals delivered from an amplifying circuit and an output limiting circuit are supplied to a comparing/discriminating circuit. The comparing/discriminating circuit consists of comparators IC6 and IC7, resistances R19-R23 and Zener diodes ZD4 and ZD5 respectively. The ON/OFF of the pulse detected by such comparing/discriminating circuit is stored in two FF2 and DD3 that work under the different conditions. The outputs of both FFs are supplied to a NOR gate NOR2. Then the ON/OFF of the final pulse is outputted through the FF5 only when the NOR2 is on or off. |
