PE (Diploma Electronics and Communication Engineering 5th)

1. Introduction to thyristors and other Power Electronics Devices (13 hrs)

a) Construction, Working principle of SCR, two transistor analogy of SCR, V-I

characteristics of SCR.

b) SCR specifications and ratings.

c) Different methods of SCR triggering.

d) Different commutation circuits for SCR.

e) Series and parallel operation of SCR.

f) Construction and working principle of DIAC, TRIAC and their V-I characteristics.

g) Construction, working principle of UJT, V-I characteristics of UJT. UJT as relaxation

oscillator.

h) Brief introduction to Gate Turn off thyristor (GTO), Programmable Uni-junction

Transistor (PUT), MOSFET.

i) Basic idea about the selection of Heat sink for thyristors.

j) Applications such as light intensity control, speed control of universal motors, fan

regulator, battery charger.

2. Controlled Rectifiers (07 hrs)

a) Single phase half wave controlled rectifier with load (R, R-L)

b) Single phase half controlled full wave rectifier with load (R, R-L)

c) Fully controlled full wave bridge rectifier.

d) Single phase full wave centre tap rectifier.

3. Inverters, Choppers, Dual Converters and Cyclo converters. (12 hrs)

a) Principle of operation of basic inverter circuits, concepts of duty cycle, series and parallel

Inverters and their applications.

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b) Choppers: Introduction, types of choppers (Class A, Class B, Class C and Class D). Step

up and step down choppers.

c) Dual Converters and cyclo converters: Introduction, types and basic working principle of

dual converters and cyclo converters and their applications.

4. Thyristorised Control of Electric drives (10 hrs)

a) DC drive control

i) Half wave drives

ii) Full wave drives

iii) Chopper drives (Speed control of DC motor using choppers)

b) AC drive control

i) Phase control

ii) Constant V/F operation

iii) Cycloconverter/Inverter drives.

5. Un interrupted Power Supply (UPS) (06 hrs)

a) UPS: Block Diagram & specifications of on-line, off line and Smart UPS

b) Concept of high voltage DC transmission