EEA1501_PRACTICAL
PRACTICAL GUIDE
Electrical Engineering I (Practical)
EEA1501
Semester 1 and 2 Module
Electrical Engineering
IMPORTANT INFORMATION:
This study guide contains important information
about your module.
Dear Student
This study guide contains the practical experiments to be completed for the module ELEPRA1.
Please note the following:
• If you have received a kit in 2021/2022, you can use that same kit to do your experiments
this year.
• Do the experiments and fill in your results on the applicable pages.
• Create your own cover page for the practical, detach the experiment pages, and submit
as your Assignment 2 for this module.
• It is recommended for you to use the workbench software, NI MultiSim to confirm your
practical results. However, all your experimental practical and simulated results must be
submitted.
• Please note that an ECSA registered professional mentor is preferable but not required
at this level. If you cannot find an ECSA registered professional mentor, any
professional person may be your mentor. This person must supervise your experiments
to verify that you have submitted your own work.
• Students must provide their own multi-meter.
Frequently asked Q And A’s About EEA1501 Practical
• Where are practical held?
They are held at the UNISA, Science Campus in Florida, Roodepoort, City of Jo’burg.
• Can I do all my registered module practical in one day?
NO, all modules practical cannot be done in one day. Each module will have its own
date.
• Can I do it on my own?
YES, you can under mentorship of someone with a National Diploma or higher
qualification in Electrical Engineering.
• Do I have to travel to Science Campus in Florida?
YES, practical is only hosted in the Science Campus in Florida. So, if you will be doing
practical on campus. You will have to travel and book your own accommodation (when
necessary).
• How will I prove that I did practical with Mentor?
Your mentor will have to sign a form to indicate he /she has assisted you with practical.
We know that this was done under supervision. You will then attach that form with your
portfolio. Your portfolio must include pictures of you doing the practical.
• How do I book for practical?
You can book online from the schedule advertised. You select a date suitable to you, add
your name on the session form online on myUnisa.
2
EEA1501_PRACTICAL
Process model for laboratory experiments
Below is the process flow for performing practical at the Electrical Engineering laboratories in
the Science Campus. The module lecturer in collaboration with laboratory staff, are responsible
for the design and presentation of the practical. The module lecturer will teach the theory and
the laboratory staff will train and supervise the leaners on the use of laboratory equipment.
The quality of the laboratory practical depends on the ability and effort of the learners and is
reflected in their mark achieved for the practical experiment. Academics have no direct control
over the quality of the learner's process steps hence the difficulty in defining quality.
Module Lecturer
Study Guide
Experiments/Tas
k
Teach the Theory
Learners
Book dates
prepare and for
practical.
Laboratory Staff
Allocate Practical
dates.
Setup Practical
Create Laboratory
Assessments
Perform Practical
Assessments
Supervise
Practical
Analyze the
practical results.
Compile the final
report.
Submit final
report on Moodle
Allocate Markers
Final Practical
Mark
Above is the process flow for a typical laboratory practical. This shows the process steps for
which academic staff, learners, professional and technical laboratory staff are responsible.
3
1.
LABORATORY REQUIREMENTS
The aim of laboratory practical is to reinforce theory. Practical circuits can be built to confirm the
content of the prescribed textbook. In order to do the practical, the student will require the
equipment and components listed below:
1.1. AD2004 Analogue/Digital Trainer
1.1.1
Features of the AD2004 Analogue/Digital Trainer
•
•
•
•
•
•
•
•
•
1.1.2
+5 V, -5V, +12V and -12V
A separate 0-24V variable output
Sine wave and triangular wave with a frequency range of between 10Hz and 1KHz.
D.C offset if required.
A separate +12V to -12V square wave.
A 5V square wave for TTL
8 logic switches (0V or 5V) and 8 LED’s
Logic Probe for 5V TTL
Audio Buzzer
Using the AD2004 Analogue/Digital Trainer
We first need to familiarize ourselves with the internal connections of the breadboard as this is
where we will insert components to build circuits.
The breadboard has two sets of power rails top and bottom and they are connected horizontally
internally. The middle section has vertical connections of five holes above the break and five
holes below the break. There is no internal connection between the top five and bottom five
holes. To apply power to the breadboard power rails we must use hook wire to connect from the
+5V, +12V or + Adj to the positive rail and 0V to the negative rail as shown on the next page.
Though the AD2004 Analogue/Digital Trainer has many other features they will not be required
to be used in the experiments that follow.
4
EEA1501_PRACTICAL
The AD2004 Analogue/Digital Trainer
To familiarize yourself with the trainer, take hook-up wire and connect switch outputs to the
LED’s. When the switch is on the corresponding LED’s should light indicating a 5V output. If the
switch is off, then the corresponding LEDs should be off indicating 0V output. The trainer has
protective fuses so under normal conditions you should not do any damage to the trainer, so
explore its features!
1.2
A.C. Adaptor (Supplied with the trainer).
NB, please note that the A.C. adaptor should be plugged into the trainer before the mains
voltage is switched on or off to prevent damage to the trainer.
5
1.3 The Digital multimeter
To carry out the experiments it is necessary to use a digital multimeter. Though there are many
different types of multimeters available they all have many common features.
The multimeter consists of a Liquid Crystal Display which displays the value of the quantity
being measured. The selector dial is used to determine whether the meter will measure voltage
(A.C. or D.C.), current (A.C. or D.C.) or resistance in ohms. It is important to note that when
measuring voltage, the one probe must be inserted in the voltage socket and when measuring
current, it must be moved to the current socket marked A or Amps. Never measure voltage
when the probe is in the current socket as you will blow the internal fuse and will no longer be
able to measure current until the fuse is replaced. Some meters also have auto range but must
have different scales which requires the operator to calculate the expected measurement so
that the correct range can be selected.
1.4 Component kit
Contains various electronics and digital systems components etc.
1x
12V D.C power source
1x
Breadboard
1x
Set of jumper wires (various colors)
1x
Set of various resistors with gold tolerance band (12Ω, 15Ω, 82Ω, 100Ω. 150Ω,
220Ω, 330Ω, 470Ω, 560Ω, 1kΩ, 1.2kΩ, 1.5kΩ, 2.2kΩ, 10kΩ, 33kΩ, 1MΩ and 5.6MΩ
1x
Set of 1kΩ variable resistor
1x
Set of 1000µF capacitors
1x
PCB Slide Switch SPDT On-Off-On
1x
Digital Multimeter(s)
6
EEA1501_PRACTICAL
1.4.1
Reading Resistors
Resistors have colored stripes which enable us to establish their value in ohm’s. Each color has
a different value as shown in the table below.
Color
Value in Ohms
Multiplier
Black
0
0
100
Brown
1
1
101
Red
2
2
102
Orange
3
3
103
Yellow
4
4
104
Green
5
5
105
Blue
6
6
106
Violet
7
7
Grey
8
8
White
9
9
Color
Tolerance
Percentage
Gold
5%
Silver
10%
To calculate the value of a resistor we first need to establish where the tolerance band is. The
tolerance band is normally either gold or silver and once we have found this the band furthest
away is band 1 then band 2 and closest to the tolerance band is band 3.
Let’s assume for practice the colors are as follows:
Band 1
Brown
Band 2
Grey
Band 3
Orange
Tolerance
Gold
7
We then insert the values into the following formula:
(Band 1) (Band 2) x (Band 3)
(Brown) (Grey) x (Orange)
18 x 10 3
18000Ω or 18kΩ
Since resistors are mass produced the chances that the resistor will be exactly 18kΩ is very
remote so the manufacturer gives a tolerance band, in this case Gold, to indicate within what
values the resistor will be. Gold represents 5% therefore the value would be.
± 5% of 18kΩ
5% of 18kΩ is 900Ω therefore the minimum value would be:
18000Ω - 900Ω = 17100Ω
And the maximum value would be:
18000Ω + 900Ω = 18900Ω
So, the resistor value would lie between 17100Ω and 18900Ω.
(Please note that in your pack of components for EEA1501, you have a blue resistor with
5 color bands as follows: brown, blue, black, black, brown. This resistor is the 160Ω
with a tolerance of 1% and is not valued according to the formula above. Please use your
Multimeter to confirm the value. This resistor is to be used in the experiments where a
160Ω resistor is a required component).
1.5
Workbench Software: NI Circuit Design Suite 12.1
The National Instruments (NI) Circuit Design Suite is a suite of EDA (Electronics Design
Automation) tools that assists you in carrying out the major steps in the circuit design flow.
Multisim is the schematic capture and simulation program designed for schematic entry,
simulation, and feeding to downstage steps, such as PCB layout. Multisim also includes mixed
analog/digital simulation capability.
The Multisim MCU Module adds microcontroller co-simulation.
Ultiboard, fed from Multisim, is used to design printed circuit boards, perform certain basic
mechanical CAD operations, and prepare them for manufacturing. Ultiboard also provides
automated parts placement and layout.
Use the simulation software to virtually build and run your experiments. In instances where you
don’t have the necessary equipment, e.g., oscilloscope, the software will be very useful. The
software is intended for you to use for the following modules:
ELA1501, EEA1501 and DIG1501
8
EEA1501_PRACTICAL
1.5.1
Installing NI Circuit Design Suite 14.1
This section describes the system requirements and installation procedures for NI Circuit
Design Suite.
1.5.2
Minimum System Requirements
To run NI Circuit Design Suite 14.1, National Instruments recommends that your
system meet the following requirements:
•
•
•
•
•
Windows 2000 Service Pack 3 or later, or Windows XP
Pentium 4 class microprocessor or equivalent (Pentium III class minimum)
512 MB of memory (256 MB minimum)
1.5 GB of free hard disk space (1 GB minimum)
Open GL® capable 3D graphics card recommended (SVGA resolution video
adapter with 800×600 video resolution minimum, 1024×768 or higher
preferred)
•
1.5.3
To develop custom LabVIEW based instruments for use in Multisim, LabVIEW
8.0.x or higher is required
Installation Instructions
The NI Circuit Design Suite 14.1 installer installs all products in the suite: Multisim, Ultiboard,
and the Multisim MCU Module.
It is recommended that you close all open applications before you Install NI Circuit Design
Suite.
Unless you specify another location during installation, the NI Circuit Design Suite installation
program copies files to <Program Files>\National Instruments\Circuit Design Suite 10.0 after
you complete the following steps:
• Insert the NI Circuit Design Suite CD into the CD-ROM drive. If the CD startup screen is
not visible, select Run from the Windows Start menu and run setup.exe from your CD.
• Follow the instructions in the dialog boxes.
1.5.4
Product Activation
When you run a product in the NI Circuit Design Suite for the first time, it will prompt you to
activate a license for that product. For this you will need the Certificate of Ownership included in
the NI Circuit Design Suite 14.1 package.
For information about how to activate your software product, please refer to the Note to Users
Activation Instructions for National Instruments Software leaflet included with your NI Circuit
Design Suite 14.0 package.
9
If you do not activate a valid license, the product will run in Evaluation Mode and continue to
prompt you to activate a license on each subsequent run. Evaluation Mode is valid for 30 days
following the first run of the product.
Note: To run the Multisim MCU Module, place a component from the MCU Module group on a
Multisim circuit or open a Multisim file that contains a component from the MCU Module group.
1.6
10
Annexure A: Mentors appointment Form
EEA1501_PRACTICAL
PRACTICE EXPERIMENT #1: No Marks Allocated.
Objective:
To familiarize the student with the resistors supplied in the kit, by establishing the resistor values
using color codes and the Multimeter.
Components required:
•
•
•
Resistors: Various resistors in the kit
Power Supply Unit: AD2004 Analogue/Digital Trainer
Measuring Instrument: Digital Multimeter
Procedure:
Complete columns 1 to 8 of the table on page 12 by inserting the value of each color band using
your knowledge gained from page 7 - 8.
Then take the Multimeter and test the resistor and place the measured value in column 6.
Repeat this for all the different resistors in your kit.
11
Results of Experiment
Name:
Student No.:
Date:
Band 1
Band 2
Band 3
1.
%
Tolerance
Color Code
Value
Multimeter
Reading
2.
3.
4.
5.
6.
7.
8.
To analyze the data taken in this experiment, the student should calculate the percentage
difference between the measured and colour-coded values of each resistor. This calculation will
be performed in the following manner:
Percentage difference (% Diff.) = colour-code value – measured value x 100%
measured value.
•
Show your calculations for anyone given resistor here …
Resistor #5
=
Do the measured values fall within the values calculated with respect to the manufacturer’s
tolerance? YES / NO
?
(0)
12
EEA1501_PRACTICAL
PRACTICE EXPERIMENT #2: No Marks Allocated.
Objective:
To familiarize the students with series and parallel resistor networks.
Components required:
• Resistors: 150Ω, 220Ω, 330Ω
• Power Supply Unit: AD2004 Analogue/Digital Trainer
• Measuring Instrument: Digital Multimeter
Procedure: Series circuit
Build the circuit as shown below using the required components.
The three resistors are connected in series due to the interconnections on the breadboard. Note
the vertical boxes show how the resistors are connected internally on the breadboard.
•
Calculate the total resistance and complete the table on page 15.
•
Set your Multimeter to measure resistance readings. Measure the resistance
between points A and B as shown on the diagram above.
13
Procedure: Parallel circuit
Build the circuit as shown below using the required components.
Note the jumper wires used between the top two resistor and the 330Ω resistor. This is since
there is no connection in the breadboard between the top half and the bottom half.
14
•
Calculate the total resistance and then complete the table on page 15.
•
Set your Multimeter to measure resistance readings. Measure the resistance
between points A and B as shown on the diagram above.
EEA1501_PRACTICAL
Results of Experiment
Name:
Student No.:
Date:
Table of results: Series Circuit
Calculated
Resistance
Are your results within % tolerance?
Measured
Resistance
YES / NO
% Difference
?
Table of results: Parallel Circuit
Calculated
Resistance
Are your results within % tolerance?
Measured
Resistance
YES / NO
% Difference
?
(0)
15
/ 100
Score
:
Your name
:
Student No.
:
Module Name
: Electrical Engineering I
Module Code
: EEA1501
Purpose
: Practical Assessment
Venue
: _______________________
Date
: _______________________
Lab. Technician
: Mrs. Lungile Nhlapo
No. of Pages
: _____
Due date
: _______________
=
__%
EXPERIMENTS #
/ 20
2. Combined series/parallel circuit.
/ 20
3. Kirchhoff’s voltage and current laws.
/ 30
4. Delta - Star transformations.
/ 15
5. Capacitor charging and discharging.
/ 15

1. Voltage and current dividing rule.
16
EEA1501_PRACTICAL
EXPERIMENT #1
1.1
Objective:
To demonstrate voltage and current dividing rule
1.2
•
•
•
1.3.1
Components required:
Various Resistors: 270Ω, 100Ω, 470Ω, 1.2kΩ, 220Ω, 560Ω
Power Supply Unit: AD2004 Analogue/Digital Trainer
Measuring Instrument: Digital Multimeter
Procedure: Voltage dividing law.
E
12V
R1
R2
270Ω
100Ω
R3
470Ω
•
Calculate the voltage drops across the various resistors in the circuit.
•
Build the circuit above on your AD2004 Analogue/Digital Trainer …
•
Measure the voltage across each resistor and then complete Table 1.1 on page 19.
17
1.3.2 Procedure: Current dividing law
R1
1200Ω
R2
220Ω
E
12V
R3
560Ω
•
Calculate the current flowing in the various branches in the circuit.
NB, because you only having one ammeter. You will have to take the current
readings one at a time.
18
•
Build the circuit above on your AD2004 Analogue/Digital Trainer …
•
Measure the current through each resistor and then complete Table 1.2 on page 19.
EEA1501_PRACTICAL
Results of Experiment 1
Name:
Student No.:
Date:
TABLE 1.1: Voltage dividing law.
Calculated
Voltage drops
Measured
Voltage drops
Voltage across R1


Voltage across R2


Voltage across R3


Prove, E = V1 + V2 + V3


YES / NO
Does the sum of volt-drop equal total applied voltage? =
?

TABLE 1.2: Current dividing law.
Calculated
Current (mA)
Current passing through R1


Current passing through R2


Current passing through R3


Total Current in the circuit


Prove, I = I1 + I2 + I3


Does the sum of branch currents equal total current in the circuit?

Measured
Current (mA)
= YES / NO ? 
[20]
19
EXPERIMENT #2
2.1
Objective:
•
•
•
2.2
To demonstrate the relationship between current and voltage in combined
series/parallel circuit.
To measure the respective values of current and voltage for the different branches.
To demonstrate the current and voltage divider rules
Components required:
•
•
•
2.3
Resistors: 100Ω, 330Ω, 270Ω, 220Ω and 33kΩ
Power Supply Unit: AD2004 Analogue/Digital Trainer
Measuring Instrument: Multimeter
Procedure: With reference to the circuit below…
•
•
•
•
•
Calculate the total resistance of the circuit.
Measure total resistance of the circuit.
Using the current divider rule, calculate and then measure the current flowing in
resistor R5.
Using the voltage divider rule, calculate and then measure the voltage-drop across
resistor R3, using the voltage divider rule. Calculate the voltage across AB and R3.
Build the circuit below on your AD2004 Analogue/Digital Trainer …
R1
A
100Ω
E
12V
B
Complete Table 2 on page 22.
20
R2
330Ω
R4
330Ω
R3
270Ω
R5
220Ω
R6
33kΩ
EEA1501_PRACTICAL
Calculation: Total Resistance
Calculations: Current in R5
Calculations: Voltage across R3
21
Results of Experiment 2
Name:
Student No.:
Date:
TABLE 2: Series/ Parallel circuits

Calculated
Results
22
Measured
Currents/Voltage
Current passing through
R5
Volt-drop across R3




Volt-drop across terminal
AB


[20]
EEA1501_PRACTICAL
EXPERIMENT #3
3.1
Objective:
•
3.2
To demonstrate Kirchhoff’s voltage and current laws on a combined series parallel
circuit using Analogue/Digital Trainer.
Components required:
•
•
•
Resistors:
R1 = Brown-Green-Black-Gold
R2 = Grey-Red-Black-Gold
R3 = Yellow-Violet-Brown-Gold
R4 = Orange-Orange-Brown-Gold
R5 = Brown-Red-Red-Gold
Power Supply Unit: AD2004 Analogue/Digital Trainer
Measuring Instrument: Digital Multimeter
Procedure: With reference to the circuit below…
•
•
Calculate and measure total resistance of the circuit.
Build the circuit below on both the AD2004 Trainer
Build the circuit below then complete table 3.1 and 3.2 on page 25.
R1
R3
R5
E
12V
R4
R2
23
Calculation: Total Resistance
Calculations: All branch currents
= I4
Calculations: All voltage-drops in the circuit
24
EEA1501_PRACTICAL
Results of Experiment 3
Name:
Student No.:
Date:
TABLE 3.1: Kirchhoff’s voltage law:
Calculated
Measured
Results
Results
Voltage 1


Voltage 2


Voltage 3


Voltage 4


Voltage 5


Total Voltage


Prove,
E = V1 + V2 + V3 + V4

E = V1 + V2 + V5

= YES /NO
Does the sum of volt-drop equal total applied voltage?
?

TABLE 3.2: Kirchhoff’s current law:
Calculated
Measured
Results
Results
Current 1


Current 2


Current 3


Current 4


Current 5


Total Current


Prove,
I1 = I3 + I5

I2 = I4 + I5


Does the sum of branch currents drop equal total current?
= YES / NO ?

[30]
25
EXPERIMENT #4
•
4.1
Delta - Star transformations.
Objective:
•
4.2
To take a delta circuit, build the equivalent star circuit and determine the calculated
and measured values of resistance and current using a 12V D.C. supply
Components required:
•
•
•
•
4.3
Various Resistors: 160Ω, 270Ω, 560Ω, 220Ω and 330Ω
Set of 1kΩ variable resistor
Power Supply Unit: AD2004 Analogue/Digital Trainer
Measuring Instrument: Digital Multimeter
Procedure:
•
Build the circuit below on your breadboard and measure the total resistance.
A
B
270Ω
220Ω
160Ω
C
560Ω
•
26
XMM1
330Ω
Now do a transformation on delta ABC and calculate the values of star Ra, Rb and Rc.
EEA1501_PRACTICAL
We can also use the 1kΩ potentiometers to get the values of resistors 160Ω, Ra, Rb and Rc,
calculated. A potentiometer is basically a variable resistor. The diagram below left shows the
physical appearance and, on the right, a schematic view of a variable resistor. Please note that
points A, B and C on the potentiometer below are not related to points A, B and C of the deltastar transform above.
To adjust the resistance, we insert a screwdriver in the top and turn the dial. From the
schematic we can see that between points A and C the resistance remains constant.
However, as we turn the dial, point B moves and resistance AB and BC vary. If resistance AB
increases resistance BC decreases and vice versa.
We will need three potentiometers. One for Ra, one for Rb and one for Rc. Once we have set
the potentiometers to the correct value we must insert them into the correct place for Ra, Rb and
Rc as in the circuit at the top of the page and measure the total resistance as shown.
•
•
Build the circuit below on your breadboard and measure the resistance before and
after the conversion.
If a voltage of 12V D.C. is applied to the circuit, measure the total current.
27
Results of Experiment 4
Name:
Student No.:
Date:
•
The original measured total resistance?
•
Build the circuit below then complete the table on page 28.
•
After conducting a Delta to Star transformation, the new resistance is

Calculated
Results
28
Measured
Results
Total Resistance (Before)
Ω

Ω

Total Resistance (After
Coversion)
% Difference between the
resistances before and
after
Total Current (Before)
Ω

Ω

%

%

mA

mA

mA

mA

Total Current (After
Conversion)
[15]
EEA1501_PRACTICAL
EXPERIMENT #5
•
5.1
Capacitor charging and discharging.
Objective:
•
5.2
To familiarize the student with the charging and the discharging characteristics of a
capacitor as well as time constant calculations.
Components required:
•
•
•
•
•
1kΩ resistor
1000μF capacitor
Power Supply Unit: AD2004 Analogue/Digital Trainer
NI MultiSim simulation software (optional)
Measuring Instrument: The Multimeter
5.3
Procedure:
5.3.1
Charging of capacitors
•
Build the circuit below…
Switch
position #1
R = 1000Ω
+
E = 12V
-
+
C = 1000µF
V
-
WARNING: Ensure that the capacitor is inserted the correct way around. The negative terminal
must be connected to the 0V of your AD2004 Analogue/Digital Trainer. Failure to do so could
result in injury as the capacitor may explode.
Close the switch and time how long it takes for the capacitor to reach steady state. (E = 12Vd.c)
29
5.3.2
Discharging of capacitors
Build the circuit below:
Switch
position #2
R = 1000Ω
+
E = 12V
-
+
C = 1000µF
V
-
Note the capacitor should be fully charged from the first experiment. Now remove the power
supply and replace it with a short circuit. Now close the switch and time how long it takes for the
capacitor to discharge (E = 0V)
•
30
How to connect the circuit on the simulation software
EEA1501_PRACTICAL
Results of Experiment 5
Name:
Student No.:
Date:
Calculate and measure the charging time
=
______ and
Calculate the time constant, T
=
______
Is the charge time equal to five-time constants? =
YES / NO
Calculate and measure the discharging time
=
______
Calculate the time constant, T
=
______
Is the charge time equal to five-time constants? =
YES / NO
______
?

and
?
______ 

On graph paper plot a curve of the charging characteristics of the circuit. The horizontal plane
should be time and the vertical plane voltage.


[15]
31
Annexure A: Mentors Forms
UNISA, Program Group Engineering,
SUBMIT THIS FORM WITH THE RESULTS OF YOUR PRACTICAL
EXPERIMENTS/PORTFOLIO
Module Code: EEA1501
ELECTRICAL ENGINEERING I - PRACTICAL
Mentor Appointment
Student number:
................................................
Student name:
................................................
Employer:
................................................
Particulars of mentor:
Name:
.........................................
Address:
........................................
.........................................
.........................................
.........................................
Employer:
..............................................
Telephone number:
.............................................. (W)

............................................... (H)
32
Qualifications:
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Capacity at work:
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