摘要 |
A process and device are provided for detecting frequency variations of waveforms (10). The waveform (10) is sensed and a first signal (16) is provided with each occurrence of the sensed waveform (10). Each time that the first signal is provided, a measuring pulse (24) that is different in duration than the sensed waveform (10) is provided. The sensed waveform (10) and the measuring pulse (24) are simultaneously transmitted to a gate (28) which provides a signal at its output to indicate if the frequency of the sensed waveform has varied more than a predetermined amount. |