| 摘要 |
PURPOSE:To find the frequency of fundamental wave from the signal that contains many higher harmonics by detecting the peak of periodic input signal wave form, by sample-holding and rectifying its output. CONSTITUTION:The signal to be detected, which contains many higher harmonics, is fed to the peak value detecting circuit 1 to detect the peak value. Its output is provided to the octave separating circuit 3 as a band discriminator. The output of octave separating circuit is fed to the frequency detecting circuits 4a-4n, the light emission diode 39-42 corresponding to the frequency band to which the fundamental wave belongs is lighted. An erred detection can be prevented by checking the frequency detection output by means of an output of the OR circuit 43. |
