problem 1)a) Distinguish between linear and switch mode power supplies.

b) Derive the output voltage expression for a buck dc-dc converter with ideal switch and diode. Design the component values to make sure continuous conduction mode.

problem 2)a) describe the working principle of a push pull dc-dc converter. Sketch the appropriate waveforms. Comment on its power handling capabilities.

b) With neat circuit and waveforms, describe the working principle of Fly-Back converter. Derive the output voltage expression in continuous current conduction.

problem 3)a) Describe clearly the effect leakage inductor resistance on the performance of boost converter.

b) Design a buck converter for the following specifications: Vo = 5V, Vs = 18V, load voltage and inductor current ripples not to exceed 2% of the average values, load current = 5A, switching frequency fs = 40 kHz. Determine the maximum and minimum values of inductor current.

problem 4)a) Make a Technical comparison between hard and soft switching circuits.

b) With a neat circuit diagram and waveforms, describe the operation of Buck based zero current switching dc-dc converter, and also derive the expression of output voltage.

problem 5)a) prepare brief notes on ON-line UPS system.

b) With a neat circuit diagram and waveforms, describe the working principle of a parallel loaded resonant converter, when the resonant frequency (ωo) is less than the switching frequency (ωs). Also obtain the output voltage expression in terms of circuit elements.

problem 6)a) Describe how the current mode control is gaining popularity over conventional PWM controllers in power supply applications.

b) Obtain the state space averaging model of a buck dc-dc converter.