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INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

Solve any one question from Q.1(a,b,c) &Q.2(a,b,c)
1(a) Draw steady state characteritics of SCR. Explain IL, IH, VBO, VBR, & show them on the characteristics.
7 M
1(b) Explain two transistor analogy of an SCR. Drive anode current equation of SCR.
7 M
1(c) Draw the circuit diagram of Gate Drive circuit for IGBT. Explain its operation.
6 M

2(a) Draw the construction of Power MOSFET and explain steady state characteristics of Power MOSFET. Compare it with SCR and IGBT.
7 M
2(b) Explain 180 degree conduction method of three phase Voltage Source Inverter for balanced star connected resistive load.
6 M
2(c) Draw the circuit diagram of single phase Full Controlled Bridge rectifier with R-L load. Explain its operation. Draw the waverform of output voltage and Current.
7 M

Solve any one question from Q.3(a,b) &Q.4(a,b)
3(a) What is DC to DC converter? Explain different methods for controlling the output voltage of Chopper.
9 M
3(b) Draw the circuit diagram of single phase AC Voltage controller with R load. Explain its operation. Draw the waveform of output voltage.
9 M

4(a) In a dc chopper, the average load current is 30 Amps, chopping frequency is 250Hz, supply volatge is 110 volts. Calculate ON and OFF periods of the chopper if the load resistance is 2 ohms.
9 M
4(b) Draw the block schematic of SMPS and explain its advantages over Linear Power Supply.
9 M

Solve any one question from Q.5(a,b) &Q.6(a,b)
5(a) Explain On-line UPS with neat block diagram. State its specifications and applications.
6 M
5(b) Explain with circuit diagram working of single phase seperately excited DC motor derive. Draw neat waveforms across load.
10 M

6(a) Compare ON-Line & OFF-Line UPS. Justify why ON-Line UPS is better.
8 M
6(b) Explain electronic ballast. What are the advantages of fluorescent lamp over conventional lamp?
8 M

Solve any one question from Q.7(a,b) & Q.8(a,b)
7(a) Explain SLR half bridge DC/DC converter with neat circuit diagram and Waveforms.
8 M
7(b) Explain dv/dt, di/dt and snubber circuit in detail.
8 M

8(a) Explain with circuti diagram and neat waveforms ZCS resonant converters.
10 M
8(b) Explain overvoltage and over current protection circuits.
6 M

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