| 摘要 |
PURPOSE:To attenuate or eliminate a single shot or periodical noise which has a rise time and a fall time longer than the duration of a pulse signal to be measure, by converting the pulse signal to be measured to a three-pulse train including an input pulse and two delay pulses and not only reducing the noise in accordance with a ratio of the rise time and the fall time to a delay time but also converting the noise to a single pulse having a short time width and allowing this pulse to pass a multiplying circuit. CONSTITUTION:In case of the noise whose rise time taun is longer than the delay time, the first phase shift subtracting means 11 delays one input signal of a subtracting circuit 13 by a time Td to reduce the noise, and the second phase shift subtracting means 14 delays one input signal of a subtracting circuit 16 by the time Td furthermore to separate the noise to plural single pulses, and a noise eliminating circuit 17 controls overlap of single pulses to make the multiplication result of zero, and thus, the noise is reduced considerably as the whole. |
