4-37
harmonics and indicates the approximate value of the cutoff frequency (XC = R). The table clearly shows
that the cutoff frequency lies between the fifth and seventh harmonics. Between these two values, the
capacitive reactance will equal the resistance. Therefore, for all harmonic frequencies above the fifth, the
majority of the output voltage will not be developed across the output capacitor. Rather, most of the
output will be developed across R. The absence of the higher order harmonics will cause the leading edge
of the waveform developed across the capacitor to be rounded. An example of this effect is shown in
figure 4-31. If the value of the capacitance is increased, the reactances to each harmonic frequency will be
further decreased. This means that even fewer harmonics will be developed across the capacitor.
Figure 4-30.—Partial integration circuit.
Figure 4-31.—Partial integration.
