Module 04 B2. 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;
- Diode parameters: peak inverse voltage, maximum forward current, temperature, frequency, leakage current, power dissipation;
- 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
- (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.
(a)
- 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 syst components: resolvers, differential, control and torque, E and I transformers, inductance transmitters, capacitance transmitters,
- synchronous transmitters;
- Servomechanism defects, reversal of synchro leads, hunting