In Fig.4, the silicon transistor has hfe = 100, hie = 1KQ, and hoe = hre = 0. Find: a) The equivalent circuit. Vcc=12V b) The voltage gain Av = volvi. c) The input impedance Zin seen by the signal voltage source Vin. d) The output impedance Zout seen by the load resistance RL. Vino I in C₁ Fig.4 R₁ |50kΩ R₂ 10kQ2 Rc 1000 RE *0.5ΚΩ C3 C₂ Vout www +₁₁ R₁ ΊΚΩ

Q2) Design a Bridge FWR to supply a load of (1002) with the waveform shown in figure from the main power supply of (220 Vrms). Find: - 1- The transformer turns ratio (a). 2- The ripple voltage. Vot Vm = 12 V 3- The Vde value. 4- The RMS value of the output voltage. 5- The ripple factor. 6- The value of capacitor filter. Vip = 0.1 V (assume ideal diodes) T=0.01 sec. tisec) Q3) V in Design a regulated circuit to supply a constant voltage of (10 V) across a resistive load of (50 2). The input voltage is shown in the figure. The minimum current for the Zener diode operation is (Izk=5mA). Find the 15 V 15 maximum power dissipated in the Zener diode. 12.5 12 V 10

4.10 A dc-dc converter is connected to a 100 V d.c. source to supply an inductive load having 40 mH in series with 5 2 resistance. FWD is placed across the load. Load current varies between two limits of 10 A and 12 A. (a) Find the time ratio (duty cycle) and the frequency of the chopper. (b) Find the equivalent Thevenin resistance across the source and determine the average source current.

The three-phase full-wave converter shown below is used to rectify the three phase (Y-connection) source signals. The six Thyristor are triggered in the sequence shown. Sketch for firing angle (a=90°) the output voltage (Vo), the phase current, the current for any two Thyristor in any one leg, and the load current (Ia). Then calculate (a) Thyristor average and r.m.s current. (b) Supply average and r.m.s current. (c) The normalized average output voltage. (d) The maximum output voltage. [Vdc = [1 - cos(60+ a)] Vml T If the line-to-neutral voltages are defined as 11 T, T T STA T. Load I sin od sin() ex-> Solve the question sin(with your own hands the corresponding line-to-line voltages are √31% sin (out + ) ---√(4)