Toa EXES-6000, Operating And Troubleshooting

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3-3. Demodulation of PAM Signal
Both holding capacitor and lowpass filter are
necessary to demodulate the PAM signal.
(1) PAM signal potential of Fig. 9-(1) at each
sampling instant is held with the holding
capacitor.
(2) Sampling pulse elements contained in the
waveforms of Fig. 9-(2) are eliminated through
the lowpass filter.
(3) Through processes (1) and (2), the PAM signal
is demodulated into such a waveform as is
shown in Fig. 9-(3) which is identical with the
original analog signal.
3-4. Sampling Pulse
If a band-limited signal is sampled by pulses
having regular intervals of time and a frequency
equal to or higher than twice the highest signifi-
Fig.9 Demodulation of PAM Signal
cant frequency, then the sample contains all the
information of the original signal.
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