Veuillez attendre...
Donnez-nous votre avis au sujet de PATENTSCOPE ou dites-nous ce qui pourrait être ajouté ou comment nous pourrions améliorer l'interface.
The electronic frequency monitoring device uses a counter (86) for continuous measurement of the cycle time of the measured frequency, so that when the frequency dops, the cycle time increases until a given count is reached at which a flag signal is supplied, as long as the condition lasts. The first flag signal activates a flip-flop (135) in turn generating a timer (146). This triggers an alarm signal after a short delay interval unless the flip-flop (135) is reset upon the loss of the flag signal when the sound frequency is restored. A second counter (87) reset by the flag signal is used for providing a flip-flop reset signal upon reaching a given count.