Description
The physical principles themselves build initially from our understanding of the atom, the concept of electrical charge, electric fields, and the behaviour of the electron in different types of material. This understanding is readily applied to electric circuits of different types, and the basic circuit laws and electrical components emerge. Another set of principles is built around semiconductor devices, which become the basis of modern electronics. An introduction to semiconductor theory leads to a survey of the key electronic components, primarily different types of diodes and transistors.
Electronics is very broadly divided into analogue and digital applications. The final section of the unit introduces the fundamentals of these, using simple applications. Thus, under analogue electronics, the amplifier and its characteristics are introduced. Under digital electronics, voltages are applied as logic values, and simple circuits made from logic gates are considered.
On successful completion of this unit students will have a good and wide-ranging grasp of the underlying principles of electrical and electronic circuits and devices, and will be able to proceed with confidence to further study.
Learning Outcomes
By the end of this unit students will be able to:
1. Apply an understanding of fundamental electrical quantities to evaluate circuits with constant voltages and currents.
Fundamental electrical quantities and concepts:
Charge, current, electric field, energy in an electrical context, potential, potential difference, resistance, electromotive force, conductors and insulators
Circuit laws:
Voltage sources, Ohm’s law, resistors in series and parallel, the potential divider Kirchhoff’s and Thevenin’s laws; superposition
Energy and power:
Transfer into the circuit through, for example, battery, solar panel or generator, and out of the circuit as heat or mechanical. Maximum power transfer
2. Evaluate circuits with sinusoidal voltages and currents.
Fundamental quantities of periodic waveforms:
Frequency, period, peak value, phase angle, waveforms, the importance of sinusoids
Mathematical techniques:
Trigonometric representation of a sinusoid. Rotating phasors and the phasor diagram. Complex notation applied to represent magnitude and phase
Reactive components:
Principles of the inductor and capacitor. Basic equations, emphasising understanding of rates of change (of voltage with capacitor, current with inductor). Current and voltage phase relationships with steady sinusoidal quantities, representation on phasor diagram
Circuits with sinusoidal sources:
Current and voltage in series and parallel RL, RC and RLC circuits. Frequency response and resonance
Mains voltage single-phase systems. Power, root-mean-square power quantities, power factor
Ideal transformer and rectification:
The ideal transformer, half-wave and full-wave rectification. Use of smoothing capacitor, ripple voltage
3. Describe the basis of semiconductor action, and its application to simple electronic devices.
Semiconductor material:
Characteristics of semiconductors; impact of doping, p-type and n-type semiconductor materials, the p-n junction in forward and reverse bias
Simple semiconductor devices:
Characteristics and simple operation of junction diode, Zener diode, light emitting diode, bipolar transistor, Junction Field Effect Transistor (FET) and Metal Oxide Semiconductor FET (MOSFET). The bipolar transistor as switch and amplifier
Simple semiconductor applications:
Diodes: AC-DC rectification, light emitting diode, voltage regulation
Transistors: switches and signal amplifiers
4. Explain the difference between digital and analogue electronics, describing simple applications of each.
Analogue concepts:
Analogue quantities, examples of electrical representation of, for example, audio, temperature, speed, or acceleration
The voltage amplifier; gain, frequency response, input and output resistance, effect of source and load resistance (with source and amplifier output modelled as Thevenin equivalent)
Digital concepts:
Logic circuits implemented with switches or relays
Use of voltages to represent logic 0 and 1, binary counting
Logic Gates (AND, OR, NAND, NOR) to create simple combinational logic functions
Truth Tables