| 摘要 |
PURPOSE:To prevent the malfunction due to noise, by adding the front and post carriers to a FSK signal, and switching the gate of AND circuits within the present period of the front and post carriers. CONSTITUTION:An FSK signal added with front and post carriers is applied to a zero crossing amplifier circuit 2, comparators 3, 4, integrator 6, comparator 7, and FF10 via a BPF1. When the FF10 is set, the output of the circuit 2 is applied to a demodulator 12 and a logical processing circuit 13. The circuit 13 outputs a reception confirming signal g and resets the FF10 after the processing time. The signal g is the timing signal before the stop of the post carrier, but since the FF10 has the priority for reset, an AND circuit 11 is closed. Thus, the malfunction due to noise after the stop of the post carrier can be prevented. |
