IMPULSE DETECTION CIRCUIT

PURPOSE:To detect impulse for a measurement target wave form in relatively wide frequency range by reduction-processing basic wave component of the measurement target wave form extracted by digital filter and the output data of A/D convertor. CONSTITUTION:An A/D convertor 1 converts the measurement target wave form inputted in time series into digital signal in accordance with the sampling clock of the frequency substantially high compared with the measurement target wave form, and outputs it to a calculation block 2. A digital filter 3, functioning as low a pass filter, extracts the basic wave component of to-be-measured wave form from the output data of A/D convertor 1, and outputs it to a comparison calculation process part 4. The calculation process part 4, by reduction- processing the basic wave component of measurement target wave form extracted by the filter 3 and the output data of A/D convertor 1 containing impulse component, detects the impulse component contained in the measurement target wave form, and compares the value of impulse component detected with the impulse set value inputted from outside, for outputting its result as impulse detection signal.