Electronic Fundamentals Module 4

4.1 Semiconductors
4.1.1 Diodes
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.
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;
Diode parameters: peak inverse voltage, maximum forward current, temperature, frequency, leakage current, power
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
Transistor symbols;
Component description and orientation;
Transistor characteristics and properties.
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
Description and operation of logic circuits and linear circuits/operational amplifiers.
(b) — 2
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
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.
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.