ASSIGNMENT

CHAPTER-1

1)Write the name of device and draw the symbol of them:

1)IGBT 4) PUT 7) MOSFET 10) SUS

2) BJT 5) TRIAC 8)MCT 11) LASCR

3)UJT 6)GTO 9) SCS

2) Draw and Explain characteristic of SCR

3) Draw and Explain characteristics of UJT

4) Explain working of three phase full wave rectifier with the help of circuit diagram

and waveform

5) state advantages of poly phase rectifier over single phase rectifier

6) Draw circuit diagram and explain working of amplitude control method for SCR

7) Draw circuit diagram and explain a.c. load control using triac and diac.

8) Explain construction of MCT

9) Draw and Explain characteristics of IGBT

10) Explain AC load control using SCR

11) Differentiate between holding current and latching current for SCR

12) A transformer with line voltage ratio 440V/320V is used for a three phase full

wave bridge rectifier. Compute (1) Load voltage (2) PIV

13) The line voltage on six phase side is 250V for a six phase half wave rectifier.

Calculate (1) Load current (2) Ripple frequency if the load resistance is 10Ω.

14) Give the classification of thyristor family

15) Explain working of SCR by two transistor circuit analogy

CHAPTER-2

1) Explain why commutation is required for SCR

2) What is function of free wheeling diode?

3) Explain how can you select Heat sink for SCR

4) Give and explain reasons to protect SCR

5) State different methods of forced commutation of SCR and explain any one

method

6) Differentiate between natural commutation and forced commutation

7) List different methods of protection of SCR and explain snubber circuit.

8) Draw the full protection circuit for SCR combining different protection and

explain briefly

9) Justify the need of heat sink for SCR

10) Explain the turn off characteristics of SCR

11) List the conditions for SCR commutation

12) Explain class ‘A’ commutation method for SCR.

13) Why gate protection is required in SCR?

14) What factors are considered for selection of heat sink for SCR.

15) Write short notes on class D type commutation

16) What is non linear surge absorber and how it can protect against overvoltage

17) Explain power rating of SCR

18) State voltage ratings of SCR

19) Explain gate protection of SCR

20) What is commutation of SCR? Explain class E commutation in detail.

CHAPTER-3

1) Draw and explain basic circuit of d.c. chopper

2) Explain Morgan chopper in detail with circuit diagram

3) Draw circuit diagram and explain working of class B chopper

4) State basic principle of DC Chopper

5) Give classification of chopper and explain Class A chopper

6) Explain use of chopper for speed control of slip ring induction motor

7) List the applications of chopper

8) Explain Jones chopper in detail with circuit diagram

9) Explain constant frequency control method for controlling output voltage of

Chopper

CHAPTER-4

1) What are applications of Cyclo converter?

2) State basic principle of inverter.

3) State the advantage of PWM method of voltage control of inverter

4) List the active devices that can be used to build inverter

5) State the advantages of power factor improvement

6) What are causes of low power Factor

7) Explain need of voltage control of inverter

8) State advantages and application of inverter.

9) Draw the waveform of bridge type cyclo converter in which output frequency is

one fourth of the input frequency

10) Draw the circuit and waveform of single phase to single phase bridge cyclo

converter with pure resistive load.

11) State various methods of pulse width modulation (PWM) and explain any one

12) Draw and explain single phase parallel inverter with its waveform

13) Draw the waveforms for single phase half bridge inverter

14) With the help of neat sketch describe single phase series inverter

15) What is cyclo converter? State different types of cycloconverter

CHAPTER-5

1) State advantages of speed control of slip ring induction motor using chopper

2) Draw and explain a.c. static circuit breaker

3) List different methods for speed control of induction motor

4) Explain heat control using SCR.

5) Draw circuit diagram and explain speed control of universal motor with speed

regulation

6) State the methods for speed control of induction motor and explain any one with

circuit diagram

7) Draw circuit diagram and explain its working for speed regulation of D.C. motor

by armature voltage control method.

8) Explain timer circuit using IC 555

9) Explain speed control of DC drive by PLL (phase locked loop)method.

10) Explain Speed control of DC series motor

11) Explain AC timer using SCR

12) Draw circuit for speed control of slip-ring induction motor using chopper