| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic voice monitor device for the voice transmitter of a broadcasting station to give the accurate alarm even when the demodulation monitor level of the modulator output repetitively falls in a comparatively short period while the oversensitive alarm is prevented. SOLUTION: The level differences between reference input 1 and comparison input 2 are detected by the comparators 5 and 6. The level fall is delayed by τ1 by a start delay circuit 7, and a bistable circuit 8 is triggered. The output of the circuit 8 is applied to a delay circuit 9, a gate circuit 11 and a counter circuit 10 respectively. The circuit 9 has delay time τ2 and is retriggerable. The output of the circuit 9 is applied to the circuit 11 and also resets (15) the circuit 10. The outputs of both circuits 11 and 10 are mixed together (12) and outputted (14) as an alarm via an alarm circuit 13. Thus the alarm are outputted (14) when the input 2 falls in a time of (τ1+τ2) or longer and also falls repetitively. |
