IECD (Diploma Electrical Engineering 5th)

1. Introduction to SCR (18 hrs)

1.1. Construction and working principles of an SCR, two transistor

analogy, intorudction to Quadriac

1.2. SCR specifications and rating

1.3. Construction, working principles and V-I characteristics of SCRs,

DIAC, TRIAC etc.

1.4. Basic idea about the selection of heat sinks for SCR and TRIACS

1.5. Methods of triggering a Thyristor. Study of triggering circuits

1.6. UJT, its Construction, working principles and V-I characteristics, UJT

relaxation oscillator

1.7. Commutation of Thyristors

1.8. Series and parallel operation of Thyristors

1.9. Applications of SCR, TRIACS in control circuits such as light intensity

control, speed control of DC and universal motor, fan regulator,

battery charger etc.

1.10. Protection of SCRs.

2. Controlled Rectifiers (10 hrs)

2.1 Single phase half wave controlled rectifier with resistive load and

inductive load, concept of free wheeling diode.

2.2 Single phase half controlled full wave rectifier

2.3 Single phase fully controlled full wave rectifier bridge.

2.4 Single phase full wave centre tapped rectifier

2.5 Three phase full wave half controlled bridge rectifier

2.6 Three phase full wave fully controlled bridge rectifier

3. Inverters, Choppers, Dual Converters and Cyclo Convertors (20 hrs)

3.1 Inverter-introduction, working principles, voltage and current driven

series and parallel inverters and applications

3.2 Choppers-introduction, types of choppers and their working

principles and applications

 3.3 Dual converters-introduction, types of dual-converters, working

principles and applications

3.4 Cyclo-converters- introduction, types, working principles and

applications 

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4 Uninterrupted power supplies (8 hrs)

(1) UPS online, off line

(2) SMPS