| 摘要 |
PURPOSE:To prevent an erroneous discrimination due to superposition of noise and to increase the reliability of demodulated output, by making the discrimination easy, through the conversion of an input signal to a pulse signal having a large impulse ratio. CONSTITUTION:An FS modulation signal 1a is inputted to a multi-vibrator 2, which detects the zero cross point of the signal 1a, and a generated pulse signal 2a is transmitted to a delay circuit 6 consisting of a sequence circuit 5 and a multivibrator. This delay circuit 6 delays the signal 2a by a given time to transmit a signal 6a to a sequence circuit 7. On the other hand, the signal 2a is supplied to the sequence circuit 5, and the sequence circuits 5, 7 detect the time point of leading and trailing, and they are fed to a set/reset terminal of an FF8 as signals 5a, 7a. Further, the output 8a of this FF8 is fed to a judging circuit 4 as a signal 3a via a low pass filter 3 and the discrimination of either 1 or 0 is made with a specified discrimination level to obtain a demodulated output 4a. |
