PROBLEMS In Problems 4.1 to 4.6, the input voltage V. is de and positive with Switch the polarity shown. Specify how to implement the switches using a position minimal number of diodes and transistors, such that the converter 2 operates over the entire range of duty cycles 0 S D S 1. The switch states should vary as shown in Fig. 4.56. You may assume that the inductor current ripples and capacitor voltage ripples are small. For each problem, do the following: 0 DT (a) Realize the switches using SPST ideal switches, and explicitly define the voltage and Fig. 4.56 Switch control method for Prob- current of each switch. lems 4.1 to 4.6. (b) Express the on-state current and off-state volt- age of each SPST switch in terms of the converter inductor currents, capacitor voltages, and/orinput source voltage. Solve the converter to determine the inductor currents and capacitor voltages, as in Chapter 2. (d) Determine the polarities of the switch on-state currents and off-state voltages. Do the polarities vary with duty cycle? (e ) State how each switch can be realized using transistors and/or diodes, and whether the realiza- tion requires single-quadrant, current-bidirectional two-quadrant, voltage-bidirectional two- quadrant, or four-quadrant switches.