ECT4701/101/0/2014
Tutorial letter 101/0/2014
Electronics IV (Theory)
ECT4701
Year Module
Department of Electrical and Mining
Engineering
IMPORTANT INFORMATION:
This tutorial letter contains important information
about your module.
CONTENTS
Page
1
INTRODUCTION...........................................................................................................................3
2
PURPOSE OF AND OUTCOMES FOR THE MODULE ...............................................................3
2.1
Purpose ........................................................................................................................................3
2.2
Outcomes .....................................................................................................................................3
3
LECTURER(S) AND CONTACT DETAILS ...................................................................................3
3.1
Lecturer(s).....................................................................................................................................3
3.2
Department ...................................................................................................................................3
3.3
University ......................................................................................................................................4
4
MODULE-RELATED RESOURCES .............................................................................................4
4.1
Prescribed books ..........................................................................................................................4
4.2
Recommended books ...................................................................................................................4
4.3
Electronic Reserves (e-Reserves) .................................................................................................4
5
STUDENT SUPPORT SERVICES FOR THE MODULE ...............................................................4
6
MODULE-SPECIFIC STUDY PLAN .............................................................................................4
7
MODULE PRACTICAL WORK AND WORK-INTEGRATED LEARNING...................................10
8
ASSESSMENT ...........................................................................................................................10
8.1
Assessment plan .........................................................................................................................10
8.2
General assignment numbers .....................................................................................................10
8.2.1
Unique assignment numbers .......................................................................................................11
8.2.2
Due dates for assignments ..........................................................................................................11
8.3
Submission of assignments .........................................................................................................11
8.4
Assignments ...............................................................................................................................12
9
OTHER ASSESSMENT METHODS ...........................................................................................22
10
EXAMINATION ...........................................................................................................................22
11
FREQUENTLY ASKED QUESTIONS.........................................................................................22
12
SOURCES CONSULTED ...........................................................................................................22
13
CONCLUSION ............................................................................................................................22
14
ADDENDUM ...............................................................................................................................22
2
ECT4701/101
1
INTRODUCTION
Dear Student
Welcome to the subject Electronics IV (Theory) (ECT4701) at UNISA. This tutorial letter
serves as a guideline to this subject. It provides you with general administrative information
as well as specific information about the subject. Read it carefully and keep it safe for future
reference. We trust that you will enjoy this course.
2
PURPOSE OF AND OUTCOMES FOR THE MODULE
2.1
Purpose
On successfully completing this module, the learners will be able to:
Fully understand the electives, thus identify various electronic circuits, analyse and design
electronic components within various applications, identify various photovoltaic
applications, design various stand-alone photovoltaic systems, and apply extensive
faultfinding and repair
2.2
Outcomes
The learners will be able to:
Practice and manage electrical engineering activities and applications at the level expected
of a professional technologist ( engineering ).
3
LECTURER(S) AND CONTACT DETAILS
3.1
Lecturer(s)
Your Lecturer for Electronics IV is Mr M Joubert. You can contact Mr Joubert for any
theoretical questions at the following number:
Tel nr : (016) 985 5718
e-mail: martinj@vut.ac.za
Contact Times : Mondays to Fridays
18h00 to 21h00
3.2
Department
Department of Electrical and Mining Engineering:
electrical&mining@unisa.ac.za
3
3.3
University
If you need to contact the University about matters not related to the content of this module,
please consult the publication My studies @ Unisa that you received with your study
material. This brochure contains information on how to contact the University (e.g. to whom
you can write for different queries, important telephone and fax numbers, addresses and
details of the times certain facilities are open).Always have your student number at hand
when you contact the University.
4
MODULE-RELATED RESOURCES
4.1
Prescribed books

Solar Electricity-second Edition 2005 by Markvart .John Wiley & Son. ISBN: 0-
471-94161-1 or newest edition.

4.2
ANALOGUE ELECTRONIC DESIGN PRINCIPLES – NICO J. OOSTHUYSEN
Recommended books
There are no recommended books for this module.
4.3
Electronic Reserves (e-Reserves)
There are no electronic reserves for this module.
5
STUDENT SUPPORT SERVICES FOR THE MODULE
Important information appears in your my Studies @ Unisa brochure.
6
MODULE-SPECIFIC STUDY PLAN
Use your my Studies @ Unisa brochure for general time management and planning skills.
CRITICAL CROSS-FIELD OUTCOMES
This module will address the following critical cross-field outcomes.
CCFO
(x)
Assessment criteria
Problem solving: critical & creative thinking
(x)
All
Group work / Team ship
(x)
All
4
ECT4701/101
Manage & organize / Self-responsibility
(x)
All
Research
(x)
All
Communication
(x)
All
Responsibility towards environment
(x)
All
Interrelated systems / not in isolation
(x)
All
Societal / economic outcomes
(x)
All
MODULE CONTENT
Topic
Unit 1
RESISTORS
CAPACITORS
SO/
AC
AND 1.1
Learner Activity
General [P05]
Recognise the generally used E12 range
1.2
Resistors [P07]
Describe the different type of wattage in use
1.3
Capacitors [P08]
State the different capacitor values
1.4
Working voltage [P08]
Describe working voltage
1.5
Nearest available value [P09]
Explain nearest available value
1.6
Colour codes for resistors and capacitors [P09]
Recognise resistor and capacitor colour coding
Prefixes [P13]
BIASING
1.7
State the different prefixes
2.1
Getting started [P16]
Recognise how to get started
Explain how to get proper biasing
2.2
The first design [P25]
Design a single stage amplifier
5
2.3
Capacitor behaviour in amplifiers [P26]
Identify coupling capacitors
Recognise capacitor behaviour within an amplifier
circuit
Identify amplitude-frequency response within an
amplifier circuit
Understand input and output impedance
2.4
Capacitor calculations [P34]
Calculate capacitor values within an amplifier circuit
BIASING
2.5
More about input impedance [P35]
2.6
Another design example [P35]
2.7
Typical voltage gain [P37]
2.8
Some improvements [P37]
2.9
Design example of a stabilized case [P44]
Design a single stage amplifier with stabilisedbiasing
2.10 Another design example [P47]
2.11 New Q-Point with external load [P49]
Consider Q-point shift with external load change
2.12 Analysis [P56]
Analyse different biased amplifier circuits
2.13 Transistor specification [P60]
3.1
ADVANCED BIASING
Introduction [P63]
Review previous chapter
3.2
Input impedance [P67]
Use new method to determine input impedance
3.3
Design example [P69]
3.4
Advanced design example [P71]
Design more advanced amplifiers
ADVANCE BIASING
6
3.5
Special biasing 01 [P75]
3.6
Special biasing 02 [P77]
ECT4701/101
3.7
Choice of amplifier parameters [P78]
3.8
The bootstrap stage [P83]
Design the bootstrap stage
3.9
Electronic buffer [P96]
Design an electronic buffer
3.10 Node graphs [P100]
Draw node graphs for various designs
3.11 Electronic laboratory procedure [P102]
Explain laboratory procedures
3.12 Polarity of capacitors [P104]
EXERCISES
4.1
THE
TRANSISTOR 5.1
AS A SWITCH
5.2
Do exercise numbers 1 – 23 [P107]
Introduction to switching circuits [P118]
Introduce switching circuits
Various design examples [P125]
Design various switching circuits
5.3
Transistor characteristics [P127]
Explain transistor characteristics
5.4
Switching speed [P128]
Describe transistor switching speed
5.5
Inductive load [P131]
Describe inductive loads
THE COMPACT DISK
12.3 The Compact Disk [P164]
MEASUREMETNS
22.1 Impedance matching [P253]
22.2 Measuring voltage gain of amplifier [P254]
22.3 Measuring Beta of transistor [P254]
22.4 Measuring input impedance [P256]
7
22.5 Measuring output impedance [P257]
22.6 Measuring hie of transistor [P258]
22.7 Measuring hoe of transistor [P258]
22.8 Measuring low cut off frequency [P259]
22.9 Measuring high cut off frequency [P259]
Topic
SO/AC
Learner Activity
Unit 2
ELECTRICITY
THE SUN
FROM 1.1
SOLAR RADIATION
2.1
Why we need photovoltaic [P01]
Introduction [P06]
The aim of this section is to determine the solar
energy available to photovoltaic systems
2.2
Energy from the sun [P07]
Understand the nature of solar radiation at
different locations on the earth
Describe the apparent daily and yearly motion of
the sun
Show how the amount of solar radiation falling on
photovoltaic panels can be determined by
measured data
3.1
Introduction [P24]
The aim of this section is to explain how solar cells
work and how they are manufactured
SOLAR CELLS
What are solar cells? [P25]
3.2
How solar cells works [P26]
3.3
Analyse the structure of a solar cell
Silicon solar cell technology [P46]
3.4
Explain the power output from a cell in terms of
the incident energy flux and the electronic
structure of the semiconductor
8
ECT4701/101
Evaluate the cell performance by using its currentvoltage characteristic
Assess the operation of practical devices and
limits imposed on their performance
3.5
Thin-film solar cells [P62]
Identify the technological steps which are used in
the manufacture of solar cells
4.1
Introduction [P81]
The aim of this section is to survey the structure
operation and design of photovoltaic systems
Structures of a photovoltaic system [P83]
4.2
PHOTOVOLTAIC
SYSTEM
ENGINEERING
4.3
Understand the structure of a photovoltaic system,
its subsystems and the concept of sizing
The photovoltaic generator [P85]
Analyse the operation of the photovoltaic
generator in terms of modules and their electrical
characteristics
4.4
Energy storage [P93]
Examine the battery operation in photovoltaic
systems
4.5
Power conditioning and control [P98]
Evaluate the role of power conditioning and control
elements
4.6
Sizing photovoltaic systems [P110]
Size a simple system using the radiation power
supply and load power requirements
4.7
5.1
Photovoltaic-Diesel
[P120]
hybrid
energy
system
Introduction [P138]
The aim of this section is to introduce the most
common applications for solar electricity
Name a wide range of applications for photovoltaic
APPLICATION
Explain the basic features of each application
Understand why photovoltaic is a suitable option in
9
each case
5.2
Economics of PV installation [P142]
Assess the economic viability of a PV installation
7
5.3
Rural electrification [P155]
5.4
Water pumping [P163]
MODULE PRACTICAL WORK AND WORK-INTEGRATED LEARNING
The practical part of this module will be covered in the module ECTPRA4.
8
ASSESSMENT
8.1
Assessment plan
You will find your assignments for this subject in this Tutorial Letter. Assignment 1,
2 and 3 are compulsory and all assignments will be used in the calculation of your
year mark. Please send the completed assignments to UNISA before the closing
dates stated in this section.
Assignment 1 must be completed on a mark reading sheet.
The mark for Electronics IV (Theory) (ECT4701) is calculated as follows:

The year mark contributes to 20%.

The examination mark contributes to 80%
The year mark is based on all the assignment marks obtained and their contribution towards
the final year mark are as shown in the table below:
ASSIGNMENT
NUMBER
1 (Compulsory)
10%
2 (Compulsory)
45%
3 (Compulsory)
45%
TOTAL
8.2
CONTRIBUTION
TOWARDS YEAR
MARK
= 100 %
General assignment numbers
Assignments are numbered consecutively per module, starting from 01.
10
ECT4701/101
8.2.1 Unique assignment numbers
Assignment 1:
Assignment 2:
Assignment 3:
543257
543280
543289
8.2.2 Due dates for assignments
THE CUT-OFF SUBMISSION DATES FOR THE ASSIGNMENTS ARE :
Assignment 1:
21 May 2014
Assignment 2:
18 July 2014
Assignment 3:
5 September 2014
8.3
Submission of assignments
ALL ASSIGNMENTS (submitted) HAVE TO BE ATTEMPTED!!!!!!!
THE SUBMISSION OF AN EMPTY ASSIGNMENT COVER IS UNACCEPTABLE.
IT IS VERY IMPORTANT TO CONSIDER THE FOLLOWING POINTS :

NO LATE ASSIGNMENT SUBMISSIONS WILL BE ACCEPTED.

KEEP A CLEAR COPY OF THE ASSIGNMENT FOR YOUR OWN
REFERENCE.
THIS IS IMPORTANT, AS ASSIGNMENTS DO GET LOST.

SUBMISSIONS OF ASSIGNMENTS MUST BE IN ACCORDANCE WITH “MY
STUDIES @ UNISA”.
Please note that model answers for the assignments will be dispatched to all
students within 1 week of the closing date of the assignment. This implies that
you cannot submit your assignment later than the stipulated submission date.
For detailed information and requirements as far as assignments are concerned, see
the brochure my Studies @ Unisa that you received with your study material.
To submit an assignment via myUnisa:

Go to myUnisa.

Log in with your student number and password.

Select the module.

Click on assignments in the menu on the left-hand side of the screen.

Click on the assignment number you wish to submit.

Follow the instructions.
11
8.4
Assignments
THE CUT-OFF SUBMISSION DATES FOR THE ASSIGNMENTS ARE :
Assignment 1: (Compulsory)
21 May 2014
Assignment 2: (Compulsory)
18 July 2014
Assignment 3: (Compulsory)
5 September 2014
ASSIGNMENT 1
To be completed on mark reading sheet
1.
A common-emitter amplifier has very high input impedance, high voltage gain, and
high current gain.
1) true
2) false
2.
A high input impedance amplifier could be a Darlington pair.
1) true
2) false
3.
A common-collector amplifier is also known as an emitter follower.
1) true
2) false
4.
The total voltage gain, expressed as a ratio, of a multistage amplifier is the sum of the
individual voltage gains.
1) true
2) false
5.
The best selection for a high input impedance amplifier is a:
1) low gain common-emitter
2) common-base
3) common-collector
4) high gain common-emitter
12
ECT4701/101
6.
The characteristic that is not of a common-base amplifier is:
1) high input impedance
2) current gain of 1
3) medium voltage gain
4) high output impedance
7.
The characteristic that is not of an emitter-follower is:
1) voltage gain of 1
2) low input impedance
3) low output impedance
4) medium current gain
8.
The best choice for a very high power amplifier is a(n):
1) common-collector
2) common-base
3) common-emitter
4) emitter-follower
9.
Refer to Figure 6-1. The value of VC is:
1) 20 V
2) 10 V
3) 5 V
4) 0 V
13
10.
Refer to Figure 6-1. If an emitter-bypass capacitor was added, the voltage gain:
1) would not change
2) would decrease
3) would increase
4) would decrease to zero
11.
Refer to Figure 6-1. If R2 opened, VCE would be:
1) 0 V
2) 20 V
3) 10 V
4) 4.8 V
12.
Refer to Figure 6-1. If R2 opened, the value of IC would be:
1) 6 mA
2) 6.67 mA
3) 8 mA
4) 10 mA
13.
Refer to Figure 6-1. If RC opened, VE would:
1) increase
2) decrease
3) remain the same
4) be undetermined
14.
Refer to Figure 6-1. If the emitter collector shorted, the voltage VC would be:
1) 0 V
2) 20 V
3) 16.67 V
4) 3.33 V
14
ECT4701/101
15.
Refer to Figure 6-1. If the collector opened internally, the voltage on the collector
would:
1) increase
2) decrease
3) remain the same
4) be undetermined
16.
Refer to Figure 6-1. If VE = 0, the trouble might be that:
1) RE is open
2) RC is open
3) R2 is open
4) R1 is open
17.
Refer to Figure 6-2. When checking this amplifier, Vout was below normal. The
trouble might be:
1) an open C3
2) an open C4
3) C4 is shorted
4) C1 is open
18.
Refer to Figure 6-2. If VB2 was higher than normal. The problem, if any, could be:
1) C3 is shorted
15
2) R3 is open
3) BE1 is open
4) C2 is open
19.
Refer to Figure 6-2. In servicing this amplifier Vout was found less than normal. The
problem could be caused by:
1) an open C3
2) an open C2
3) an open base-emitter of Q2
4) a shorted C2
20.
Refer to Figure 6-2. The output signal from the first stage of this amplifier is 0 V. The
trouble could be caused by:
1) an open C4
2) an open C2
3) an open base-emitter of Q2
4) a shorted C4
16
ECT4701/101
ASSIGNMENT 2
Question 1
Amplifier design method
1.1
Give a detailed discussion on the effect of the load resistor R (load) on the design
approach when needed to design a common emitter class-A-amplifier.
(10)
1.2
Simple two resister biasing amplifiers have a dependence on the beta value of the
transistor. Discuss in detail how to overcome the problem of beta dependence.
(10)
1.3
Explain in detail how to measure the beta value of a transistor using an amp meter
and voltmeter.
(10)
Question 2
Practical design
2.1 Design component values for a common emitter class-A amplifier given in figure
1. Take the effect of R load into consideration by getting Q-point in the center for I
collector of 2 mA. R load is 2K7 ohms, Take h fe = 100, hie = 2000 ohms, the
voltage gain is 10 and the power supply is 20 volts.
(20)
+ Vcc
C3
R3
R1
R5
C1
C2
R2
R4
RL
Figure 1
2.2 Draw the node graphs for the design in 2.1 if the input is 10 mV peak to peak.
(10)
17
Question 3
3.1
Mathematical Analysing
The class A amplifier in figure 2 has a sine wave input of 1 kHz with a 0,5 peak to
peak amplitude. Analyse the circuit and draw the node graphs on scale from point
A to J, show all calculations.
(20)
H
2k7
39 k
A
+ 20 V
C2
J
D
B
E
C1
10 k
+
8k2
180 R
F
vg
820 R
C3
G
Figure 2 Class A- amplifier design
3.2 Will the amplifier work in practice? State your answer as yes or no. If your answer is
no, redesign the amplifier so that the amplifier will work properly. If your answer is yes
motivate.
(10)
Question 4
+5V
+5V
=1
0
0
L
o
g
icg
a
te
4
k
7
3
9
0R
L
E
D
Figure 3: Driving an LED with a PNP transistor so that the LED grounded.
The disadvantage of the circuit in figure 3 is that the “logic” output is reversed. An
“ON” signal from the gate keeps the LED off, and an “OFF” signal from the gate will
illuminate the LED. Design a circuit to correct this by using and extra transistor.
(10)
Total = 100
18
ECT4701/101
ASSIGNMENT 3
Question 1
Refer to Photovoltaic’s and answer the following questions.
1.1.
What subsystems of a PV system can you name?
(4)
1.2.
What are the main categories of PV systems?
(2)
1.3.
How do the current and voltage of a module depend on the operating conditions? (2)
1.4.
How many cells usually comprise a module? How are the cells connected and why?
(2)
1.5.
What is the role of a bypass diode?
(2)
1.6.
What are mismatch losses and how can they be reduced?
(2)
1.7.
What is the temporal pattern of battery operation in a PV system?
(2)
1.8.
Why is it a good maintenance practice to overcharge the battery at the end of winter?
(2)
1.9.
Is it true to say that the operational capacity of a battery in a PV system can be
significantly higher than the manufacturer’s specifications?
(2)
1.10. What are the disadvantages of operating battery storage as a seasonal buffer?
(2)
1.11. What is the role of the blocking diode? Is it always necessary?
(2)
1.12. How can a PV system operate without electronic control and what disadvantages
does this system design have?
(2)
1.13. What types of charge regulators are used in PV systems?
(2)
1.14. Which inverter would you use in a stand-alone domestic system?
(2)
1.15. Which control element would you use to ensure maximum power extraction from PV
generator?
(2)
1.16. Why is accurate sizing of PV installations important?
(3)
[35]
Question 2
Photovoltaic design
2.1 Refer to a city in Europe latitude 20° north. You must design a PV system and no
tables for the radiation are available. Show how to design without the irradiance
tables by stating the tilt angle and solar hour for the following:
2.1.1 The highest irradiation over the whole year.
(3)
19
2.1.2 The highest irradiation during winter months
(3)
2.1.3The highest irradiation during summer months
(3)
2.2 Refer to the data in table 1 and determine the angle of inclination and the solar
hour to be recommended in order to maximize the input to a photovoltaic (PV)
system for the following conditions:
2.2.1 The highest energy incident on the inclined panels over the whole year.
(3)
2.2.2 The month and highest energy during the winter months at 30°.
(3)
2.2.3 The month highest energy during the summer months at 30°.
(3)
2.2.4 The worst month of the year at 30°.
(2)
2.2.5 The best month of the year at 30°.
(2)
Table 1 Solar radiation for Pretoria RSA
20
ECT4701/101
Question 3
Explain with the aid of sketches how to plot the characteristic curve of a photovoltaic panel
practically. Show how to calculate the maximum power point, maximum power ratio and the
fill factor and explain the meaning of each.
(10)
Question 4
Design and size a photovoltaic system for a streetlamp at Pretoria latitude 25°44’south by
considering table 1 for the following electrical load:
1 * 100watt 12 V streetlamp operating 10 hour every day.
The use of a maximum power point tracker contributes 20% more energy transfer to the
system. Available are 50 W, 12 volt panels.
4.1
Sketches the power flow block diagram for the system.
(3)
4.2
Calculate the total daily load for the streetlight in kWh/day a seen by the PV including
the losses of the system.
(4)
4.3
From table 1 determine the tilt angle that will maximise the mean average of the
year.
(3)
4.4
From table 1 determine the solar hour for the tilt angle in 4.3.
(3)
4.5
Calculate the size and number of solar panels for this tilt angle.
(4)
4.6
Calculate the (SF) safety factor of the panels.
(3)
Question 5
Refer to question 4. If a set of batteries needed to be added to the system, design and size
the batteries for the following conditions:
Assume 2 days of storages in a battery with an efficiency of 80% and the batteries should
not be discharge to less than 50% of its capacity and the deficit annually is zero. Available
are 95 Ah, 12V batteries.
(10)
Total 100
21
9
OTHER ASSESSMENT METHODS
None
10
EXAMINATION
Use your my Studies @ Unisa brochure for general examination guidelines and examination
preparation guidelines.
11
FREQUENTLY ASKED QUESTIONS
The my Studies @ Unisa brochure contains an A-Z guide of the most relevant study
information.
12
SOURCES CONSULTED
None
13
CONCLUSION
Please ensure that you have all the tutorial letters and prescribed book available before
starting with your studies.
14
None
22
ADDENDUM