Module 4

MODULE 4. ELECTRONIC FUNDAMENTALS
4.1 Semiconductors
4.1.1 Diodes
    (a) Diode symbols;
         Diode characteristics and properties; Diodes in series and parallel;
         Main characteristics and use of silicon controlled rectifiers (thyristors), light emitting diode,                   photo conductive diode, varistor, rectifier diodes; Functional testing of diodes.
    (b) Materials, electron configuration, electrical properties;
          P and N type materials: effects of impurities on conduction, majority and minority characters;
          PN junction in a semiconductor, development of a potential across a PN junction in unbiased,               forward biased and reverse biased conditions;
         Operation and function of diodes in the following circuits: clippers, clampers, full and half                     wave rectifiers, bridge rectifiers, voltage doublers and triplers;
         Detailed operation and characteristics of the following devices: silicon
          controlled rectifier (thyristor), light emitting diode, Shottky diode, photo
          conductive diode, varactor diode, varistor, rectifier diodes, Zener diode.

4.1.2 Transistors
    (a) Transistor symbols;
         Component description and orientation;
         Transistor characteristics and properties.
   (b) Construction and operation of PNP and NPN transistors;
         Base, collector and emitter configurations;
        Testing of transistors.
        Basic appreciation of other transistor types and their uses.
        Application of transistors: classes of amplifier (A, B, C);
        Simple circuits including: bias, decoupling, feedback and stabilisation;
        Multistage circuit principles: cascades, push-pull, oscillators, multivibrators,
          flip-flop circuits.

4.1.3 Integrated Circuits
    (a) Description and operation of logic circuits and linear circuits/operational amplifiers.
    (b) Description and operation of logic circuits and linear circuits;
          Introduction to operation and function of an operational amplifier used as:
           integrator, differentiator, voltage follower, comparator;
         Operation and amplifier stages connecting methods: resistive capacitive,
          inductive (transformer), inductive resistive (IR), direct;
         Advantages and disadvantages of positive and negative feedback.

4.2 Printed Circuit Boards
      Description and use of printed circuit boards.

4.3 Servomechanisms
 (a) Understanding of the following terms: Open and closed loop systems,
       feedback, follow up, analogue transducers;
       Principles of operation and use of the following synchro system
       components/features: resolvers, differential, control and torque,
       transformers, inductance and capacitance transmitters.
 (b) Understanding of the following terms: Open and closed loop, follow up, servomechanism,                   analogue, transducer, null, damping, feedback, deadband; Construction operation and use of the           following synchro system components: resolvers, differential, control and torque, E and I                     transformers, inductance transmitters, capacitance transmitters, synchronous transmitters;
       Servomechanism defects, reversal of synchro leads, hunting. - - 2 -