Chapter 7, Problem 7.49P

Determine (a) the average and (b) rms values of the periodiccurrent waveform shown in Fig. P8.9

Find Eigenvalues and Eigenvectors for the following matrices: [5 -6 1 A = 1 1 0 3 0 1

Use Gauss-Jordan Elimination method to solve the following system: 4x1+5x2 + x3 = 2 x1-2x2-3x3 = 7 3x1 x2 2x3 = 1. -

3. As the audio frequency of Fig. 11-7 goes down, what components of Fig. 12-4 must be modified for normal operation? OD C₂ 100 HF R₁ 300 Re 300 ww 100A R 8 Voc Rz 10k reset output 3 R7 8 Voc 3 reset output Z discharge VR₁ 5k 2 trigger 2 trigger 7 discharge R 3 1k 5 control voltage threshold 6 5 control voltage 6 threshold GND Rs 2k C. C. 100 GND Uz LM555 1 Ce 0.01 U, LM555 0.01 8.01.4 PRO Fig. 11-7 Audio lutput Pulse width modulator R4 1k ww C7 Re 1k ww R7 100 VR 50k 10μ Ra R10 C₁. R1 3.9k 3.9k 0.14 100k TO w Rs 51 82 3 H 10 Carrier U₁ Ca Input A741 2.2 Us MC1496 PWM signal input R2 0.1100k Uz A741 41 Cs 1 Re 10k VR2 50k VR3 100k 14 12 C3. 3% + Ce 0.1 10μ 5 1A HH C +12V 0.1 O PWM Output C 0.02- R 100k +12 V Demodulated output 6 Ca 0.33 w R 10k R12 100k ww 31 о + 4A741 -12 V Fig. 12-4 PWM demodulator C 1500p

DUC 1. In Fig. 12-4, what are the functions of the VR1 and VR2? 2. In Fig. 12-4, what is the function of the VR3? VR₁ 50k C₁ R1 0.1 100k Carrier Input U₁ A741 PWM signal input R41k www Re 1k w C7 ± 10μT R7 100 ww =L H C4 2.2 H W82 Rs 51 3 10 U3 MC1496 C2 R2 U2 A741 22 0.1 100k VR2 50k VR3 100kr 14 C3 10μ 1k 0.1 4 5 6 12 m Re 10k R9 R102 3.9k 3.9k HHI C10 0.1 -0 +12V C11 R 0.02 100k +12 V Demodulated output C R11 R12 A741 0.33 10k 100k -12 V Ca 1μ C12 1500p PRODUC Fig. 12-4 PWM demodulator PRODUCTS

10.37 Use mesh analysis to find currents I₁, I2, and I3 in the circuit of Fig. 10.82. ML 120-90° V 120 -30° V Figure 10.82 For Prob. 10.37. N N Z=80-135

3. Find the phasor current I。 in the circuit shown below. Be aware of the direction markings. (15 pts) 1052 I 5057 ①520 Amps 2012 j5052

10.93 Figure 10.135 shows a Colpitts oscillator. Show that the ed oscillation frequency is 1 fo= 2π √√LCT where CTC₁C2/(C₁ + C₂). Assume R; >>> R₁ + Rf ww Vo L m C₂ C₁ 5 Xci Figure 10.135 A Colpitts oscillator; for Prob. 10.93. (Hint: Set the imaginary part of the impedance in the feedback circuit equal to zero.)

Determine (a) the average and (b) rms values of the periodiccurrent waveform shown in Fig. P8.3.