SWEEP STOPPING CIRCUIT

PURPOSE:To preferentially receive traffic information for moving places, by taking an amplitude modulation signal (DK signal) which is transmitted from a broadcast station only when the traffic information is broadcast as a sweep stopping signal in preference to a discrimination signal (SK signal) of the traffic information broadcast station. CONSTITUTION:When a traffic information signal level receiving at present is lowered by moving, a terminal SK' of an SK decoder 11 moves to H level and an alarm tone generating circuit 13 is operated. When the operator listens to this alarm tone, a switch S1 is closed by manual operation to start sweeping. When a DK signal is detected at the sweep of the 1st cycle after closing of the switch S1, since the SK signal is also detected, the sweep is stopped with an automatic channel selection controlling circuit 10. If no DK signal is detected during the said 1st sweep cycle, since the output of the 1st timer circuit 14 is at L level, the sweep is stopped in response to the detection of the SK signal, because the output of a gate circuit 16 is held at H level.