Chapter 7, Problem 7.9P

PROD 1. What is the function of VR, in Figs. 11-2 and 11-7. DL RO 0.014 +12V R₁ 1k ww Vin(+) 6 C₁ 0.1μ Audio input HH VRI Vin(-) 4 U1 HА741 10k ww R2 10k UCTS 0.01 μ -12V PWM output Fig. 11-2 The pulse width modulator based on μA741 +12 V ° C₂ 100 R₁ 300 Re 300 Cs 100 ww ww Vcc 4 reset 2 trigger 5 control voltage U₁ LM555 GND www R₂ T₁ 10k output 3 discharge Z Voc output 3 reset VR₁ 5k 2 trigger 7 discharge Ra 1k threshold 6 control 6 threshold voltage GND Rs CA U2 LM555 1 2k 100 Ca 0.01 Audio lutput www R7 10k O PWM C6 -0.014 Fig. 11-7 Pulse width modulator 11/9 Output

PRO3. In a point of view of voltage polarity, what is the difference between the output PWM signals in experiments 11-1 and 11-2? H ICTS Experiment 11-1.. Pulse Width Modulator Using uA741 Experiment 11-2 Pulse Width Modulator Using LM555

9.58 Using Fig. 9.65, design a problem to help other ed students better understand impedance combinations. Figure 8 65 ww C L R₁ www R2