Flyback Converters In Problems 8.1 through 8.4, in a Flyback converter, Vin = 30V, N1 = 30 turns, and N2 = 15 turns. The self-inductance of winding. The output voltage is regulated at Vo = 9 V.
1. For the same duty-ratio as in problem 8.1, calculate the critical power which makes this converter operate at the border of incomplete and complete demagnetization modes.
2. Draw the waveforms, similar to those in Problem 8.1, in Problem 8.2.
3. Consider that a Flyback converter is operating in the complete demagnetizing mode. Under this mode of operation, derive the voltage transfer ratio in terms of the transformer magnetizing inductance Lm1 seen from the input-side winding, switching frequency fs the duty-ratio D, and the load resistance R.

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w