| 摘要 |
<p>PURPOSE:To improve the signal discriminating performance by providing a counter and a pulse width checking filter at every signal. CONSTITUTION:A latch flip-flop 11 outputs a strobe signal c1 in synchronization with an input signal (b), and outputs a reset pulse d1' by the logic product of a falling differentiating pulse d1 and the signal c2. A counter 31 counts TP1=1/ (f1+DELTAf1), where f1: the general deviation of a frequency f1. The pulse TP1 resets the flip-flop 11 and operates a counter 51. The counter 51 outputs a band pulse f1 of the width of DELTAT1=1/(f1+DELTAf1)-f/(f1+DELTAf1). The band pulses f1-fn are obtained by using similar circuit for the other frequency. The signal is discriminated by the coincidence of the pulses f1-fn and the differentiating pulse d2.</p> |
