| 摘要 |
<p>A d. c. voltage (UM) depending on the pulse etc. mean frequency (fm) is derived from the periodic pulse train, and a triggering pulse is derived from each pulse. A triangular voltage (UD) is continuously derived from a generator but abruptly reset to zero by each triggering pulse. It again rises from the last zero level, with the rising time a function of the d. c. voltage (UM), and equal to the pulse train mean period. The triangular voltage is compared with a reference voltage (UR) determining the frequency tolerance limits. Its peak value is lower than that of the triangular voltage. Voltage resulting from the comparison and triggering pulses are so logically linked, that when pulse repetition frequency is within the tolerance limits, a first signal is delivered, and when it is outside the limits, a second, different signal is delivered.</p> |
