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Figure 3J.—Pcm conversion.
IN ANSWERING QUESTIONS 3-57
THROUGH 3-59, REFER TO FIGURE 3J.
3-57. To convert from pcm to pam, what type
of circuit is used to apply the pcm to the
input of the circuit shown?
1. A constant-current source
2. A constant-voltage source
3. A limiter-amplifier source
4. An oscillator-amplifier source
3-58. If C1 is allowed to charge 16 volts during
the period of one pulse, each additional
pulse increases the charge by 16 volts.
With the binary-coded equivalent of an
analog 12 applied to the input, what will
be the output of the circuit at sampling
time?
1. 10 volts
2. 12 volts
3. 14 volts
4. 16 volts
3-59. Between pulses, R1 must allow C1 to
discharge to what voltage?
1. 0 volts
2. One fourth of the charge on C1
3. One half of the charge on C1
4. Three fourths of the charge on C1
