Chapter 6, SIGNAL GENERATORS Video Solutions, Operational Amplifiers and Linear Integrated Circuits

Problem 1

Make two drawings of a multivibrator circuit with $R_1=100 \mathrm{k} \Omega, R_2=86 \mathrm{k} \Omega, R_f=10 \mathrm{k} \Omega$, and $C=0.01 \mu \mathrm{F}$. Show the direction of current through $C$ and calculate both $V_{U T}$ and $V_{L r}$ for (a) $V_o=+V_{\text {sat }}=15 \mathrm{~V}$; (b) $V_o=-V_{\text {sat }}=-15 \mathrm{~V}$.

Rubeena Zulfiqar

Numerade Educator

05:17

Problem 2

Calculate the frequency of oscillation for the multivibrator circuit in Problem 6-1.

Amit Srivastava

Numerade Educator

Problem 3

In Probiem 6-1, if $C$ is changed to $0.1 \mu \mathrm{F}$, do you expect the output frequency to oscillate at $500 \mathrm{~Hz}$ ? (See Example 6-3.) What could you do to $R_f$ to increase frequency to $1000 \mathrm{~Hz}$ ?

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Problem 4

The monostable multivibrator of Figs. 6-4 and 6-5 generates a negative output pulse in response to a negative-going input signal. How would you change these circuits to get a positive output pulse for a positive-going input edge?

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Problem 5

Explain what is meant by monostable recovery time.

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02:24

Problem 6

Sketch a one-shot multivibrator circuit whose output will deliver a negative pulse lasting $1 \mathrm{~ms}$ with a recovery time of about $0.1 \mathrm{~ms}$.

M Hassan Anwar

Numerade Educator

01:35

Problem 7

Assume for simplicity that saturation voltages in the triangle-wave oscillator of Fig. 6-6 are $\pm 15 \mathrm{~V}, R_i=R=10 \mathrm{k} \Omega, C=0.1 \mu \mathrm{F}$, and $p R=50 \mathrm{k} \Omega$. Find the peak triangle-wave voltages and oscillating frequency.

Varsha Aggarwal

Numerade Educator

00:40

Problem 8

Refer to the triangular-wave oscillator circuit of Fig. 6-6. What happens to peak output voltages and oscillating frequency if you (a) double $p R$ only; (b) double $R_i$ only; (c) double capacitor $C$ only?

Mayukh Banik

Numerade Educator

02:58

Problem 9

Change $p R$ to $14 \mathrm{k} \Omega$ and $C$ to $0.1 \mu \mathrm{F}$ in the unipolar triangle-wave generator of Fig. 6-7. Find the resulting peak output voltage and frequency of oscillation. (See Example 6-7.)

Narayan Hari

Numerade Educator

Problem 10

In the sawtooth-wave generator of Fig. 6-8(a), let $V_{\text {ref }}=1 \mathrm{~V}, R_i=10 \mathrm{k} \Omega$, and $C=0.1 \mu \mathrm{F}$.
(a) Find an expression for frequency $f$ in terms of $E_i$.
(b) Calculate $f$ for $E_i=1 \mathrm{~V}$ and $E_i=2 \mathrm{~V}$.

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Problem 11

These questions refer to the AD630 balanced modulator circuit in Fig. 6-9.
(a) Name the application for which the AD630 is wired.
(b) When pin 9 is at a positive voltage, which amplifier is selected, and what is the value of $V_o$ ?
(c) Suppose that $V_{\text {ref }}$ is a $\pm 1-\mathrm{V}$-peak sine wave and pin 9 is at $1 \mathrm{~V}$; what happens at $V_o$ when pin 9 is changed to $-1 \mathrm{~V}$ ?

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01:43

Problem 12

Figure 6-I0 shows a precision triangle/square-wave oscillator. Three components control peak output voltages and oscillating frequency, $R_i, C$, and $V_{\text {ref }}$.
(a) Which does what?
(b) Can the oscillating frequency be adjusted independent of peak outputs, and vice versa?
(c) What must be done to change the frequency from 100 to $500 \mathrm{~Hz}$ and the peak voltages from $\pm 5 \mathrm{~V}$ to $\pm 1 \mathrm{~V}$ ?

Vishal Gupta

Numerade Educator

02:51

Problem 13

$V_o=0.866 \mathrm{~V}$ in the sine function generator circuit of Fig. 6-11.
(a) What angle does this represent?
(b) What is the value of the input angle voltage?