Control signal detection system

Abstract

Abstract PURPOSE: To detect definitely an automatic stop control signal, etc., existing by detecting the existence of a control signal formed of signals mutually differing in frequency, by counting changes in frequency of the control signal to a fixed number. CONSTITUTION: Detector 5 equipped with band-erasing circuit 11, rectifying integral waveform forming circuit 12, inverter 13, BFP15, rectifying integrating circuit 16, AND gate 14, etc., generates a detection pulse of width equivalent to the existence period of signal (f 1 ) of the control signal formed of mutually-different frequencies (f 1 ) and (f 2 ) without being influence by noises. In response to this pulse, the monostable multivibator of input-change detection circuit 7 generates a pulse of a little bit wider width to open AND gate H. On the othe hand, a pulse outputted at the time of a change between signals (f 1 ) and (f 2 ) outputted by gate 24 applied with a detection pulse of signal (f 2 ) from similar detection circuit 6 is counted by counter 8. When this count value reaches a fixed value, an existence detection signal of the control signal is generated through monostable multivibrator 9. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Shigeru Yamazaki

Bibliographic Details