Answer the following problems.

problem 1) Describe the PLR dc-dc converter working in continuous-conduction mode operation with ω_s<ω_O. Draw the appropriate circuit diagram and waveforms and develop the voltage equations.

problem 2) A zero current switching dc-dc buck converter has the following data: V_S=30V, V_O=15V, R_O=5Ω, f_S=200 KHz. Determine the values of L_r and C_r, such that the maximum current in the inductor is 15A.

problem 3) Describe the state space averaging technique as applied to dc-dc buck converter modelling.

problem 4) Describe the current mode control as applicable to dc-dc converters. What are its advantages over conventional direct duty ratio pwm control?

problem 5) What are the typical power supply disturbances? Describe how they can cause problems to critical loads.

b) prepare a technical note on:

i) On-line UPS system

ii) EMI and RFI filters