04) A converter is feeding an RL load as shown in Fig. 2 with Vs = 220 V, R = 52, L = 7.5 mH, f=1 kHz, d=0.5, and E=0 V. Calculate (a) the minimum instantaneous load current (b) the peak instantaneous load current, (c) the maximum peak-to-peak load ripple current, (d) the average value of load current la, (e) the rms load current lo, (f) the effective input resistance Ri seen by the source, (g) the rms chopper current, and (h) the critical value of the load inductance for continuous load current. Chopper FWD 500000 R Fig.2 LL

Q1) The buck converter has an input of 50 V and an output of 25 V. The switching frequency is 100 kHz, and the output power to a load resistor is 125 W. Determine: (a) the duty ratio. (b) the value of inductance to limit the peak inductor current to 6.25 A. (c) the value of capacitance to limit the output voltage ripple to 0.5 percent.

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

An unipolar PWM full bridge circuit has a Vr.rms of 125V at a duty cycle D1 of 0.7. What is Vd? What is Vo.rms?

For the given BJT circuit, determine the operating point and plot the DC load line showing the Ic(sat) and Vce(max). 16 V 510 k2 Ing Ico 1.8kQ2 VC Vcto B-120

5. A single phase full converter connected to 230V, 50Hz is feeding a load R=1002 in series with large inductance that make the load current ripple free for firing angle of 45°. Determine the efficiency, form factor and displacement factor.

Q1. a) Figure Q1 is a single phase 2-level voltage source converter (VSC) with a total DC voltage V-1000V. A PWM scheme, by comparing a reference value with a 1kHz triangular waveform, is used to control the switches S₁ and S2, and output 340v at Vo. With the aid of graphs explain how pulse signals for the switches are generated, sketch the output voltage Vo, determine the duty cycle and the modulation index. Va + 2 it Va d + TS₁ V {1+5₂ = Figure Q1 A single phase VSC

(b) A single-phase full converter charges a battery which offers a constant value of E. A resistor R is inserted to limit the battery charging current. Derive an expression for the average charging current. Find the value of R in case of battery charging current is 6 A, supply voltage is 40 V, 50 Hz, E=12 V and voltage drop in conducting SCR is 1 V determine: (i) Power dissipated in R (ii) Supply power factor

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)

A buck-boost converter operates with an input battery. It converts +12 V to –12 V at apower level of about 75 W. the switching frequency is 120 kHz. The switches have200 ns switching time. The battery has an internal series resistance of 0.2  and seriesinductance of 200 nH. (a) What is the operating value of the duty ratio? What power is lost in the battery resistance? (b) Propose an interface structure to improve operation and decrease losses. What are the duty ratio and battery         resistance loss with your interface in place?