| 摘要 |
PURPOSE:To make electric noise and impact sound adequately discriminatable by removing electric noise by utilizing the difference in time width between the signals by the electric noise and the impact sound. CONSTITUTION:An input signal 4 is applied via a comparator 6 to a pulse generator 7 after full wave rectification 5. The pulses generated at the rise and fall of input pulses are inputted to a monostable multivibrator (multi) 8, and the output from the multi 8 is applied to generators 9, 10. The pulse at the rise from the generator 9 is delayed 13 by the pulse time width of the multi 8 and is used as a start pulse for a clock device 11. The pulse at the fall from the generator 10 is used as a stop pulse for the device 11. The output of the device 11 is supplied to a decision circuit 12, by which it is compared with a set count value and when it is larger than said value, it is decided as an impact signal. |
