ELECTRICAL ENGINEERING DEPARTMENT
ACADEMIC SESSION: _____________
DET20033 – ELECTRICAL CIRCUITS
PRACTICAL WORK 5 : TRANSFORMER
PRACTICAL WORK
DATE :
LECTURER’S NAME:
GROUP NO. :
TOTAL
STUDENT ID & NAME : MARKS
(100%)
(1)
(2)
(3)
DATE SUBMIT : DATE RETURN :
1 LEARNING OUTCOMES (LO)
Construct of an AC electrical circuit and measured related electrical parameter using
appropriate electrical equipment. ( P4 , PLO 5 )
2 OBJECTIVE
At the end of this practical work, student should be able to:
1. Understand the operations of transformer which is step up transformer, step down
transformer and the effect of resistive load across the secondary winding.
3 THEORY
Transformer is an electrical device that transfers electrical energy between two or more
circuit through electromagnetic induction. Electromagnetic induction produces an
electromotive force across a conductor which is exposed to time varying magnetic fields.
Transformer is used to increase or decrease the voltage of alternating current in electric
power applications.
Figure 5.1 : Transformer
4 EQUIPMENT / TOOLS
i. AC power Supply 1 unit
ii. AC Voltmeter 2 units
iii. Digital Multimeter 1 unit
iv. Rheostat 1 unit
5 PROCEDURE
PART A
i. Using the single phase transformer labeled 0-240 as primary winding and 0-
120,120-240 as secondary winding.
ii. Set the Workbench Power supply to 50V, 50Hz indicated by digital multimeter.
Connect the power supply 50V, 50Hz to primary winding labeled 0-240 as shown
in Figure 5.2.
iii. By using the digital multimeter, measure primary voltage, V1 at terminal 0-240
and secondary voltage, V2 at terminal 0-120. Write down the results into the
Table 5.1.
iv. Add load at secondary winding (V2 at terminal 0-120), measure the output value
and record the results into the Table 5.1.
I1
240
240
IL
VS V1 120
50V, 50Hz V2 Load,
R = 50Ω
0 0
Figure 5.2
PART B
i. By using the same single phase transformer, labeled 0-240 as secondary winding
and 0-120 as primary winding.
ii. Connect the Workbench Power Supply 50V, 50Hz to primary winding, 0-120 as
shown in figure 5.3.
iii. By using the digital multimeter, measure primary voltage, V1 at terminal 0-120 and
secondary voltage, V2 at terminal 0-240. Write down the results into the Table 5.1.
iv. Add load at secondary winding (V2 at terminal 0-240), measure the output value
and record the results into the Table 5.1.
I1 0 0 IL
VS V1
Load,
50V, 50Hz V2 R = 50Ω
120
240 240
Figure 5.3
6. RESULT
Table 5.1
Primary Secondary Type of Load Primary
Part
Voltage, V1 Voltage, V2 transformer Current, IL Current, I1
B
7 DISCUSSION
1. State the relationship (greater than > or smaller than <) for Np, Ns, Vp, Vs, Ip and Is for
each of the following transformer. [ /6 M]
Type Of
Characteristic Of Transformer Relationship
Transformer
1. Number of turn Np Ns
Step-up
Transformer
2. Voltage transformation Vp Vs
3. Current transformation Ip Is
1. Number of turn Np Ns
Step-down
Transformer
2. Voltage transformation Vp Vs
3. Current transformation Ip Is
2. The function of transformer is to [ /3 M]
3. Three (3) types of transformers are [ /3 M]
i. ___________________________________
ii. ___________________________________
iii. ___________________________________
4. What happen if there is no resistive load across the secondary winding? [ /3 M]
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8. CONCLUSION
Based on the work performed, [ /5 M]
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PRACTICAL EVALUATION FORM
PRACTICAL WORK 5: TRANSFORMER
1. PRACTICAL WORK ASSESSMENT – 100%
NO. A. PRACTICAL SKILL ASSESSMENT S1: S2: S3:
1. Circuit connections ⑤④③②① ⑤④③②① ⑤④③②①
2. Voltmeter connection & readings ⑤④③②① ⑤④③②① ⑤④③②①
3. Ammeter connections & readings ⑤④③②① ⑤④③②① ⑤④③②①
4. Transformer characteristics ⑤④③②① ⑤④③②① ⑤④③②①
5. Result 1 ⑤④③②① ⑤④③②① ⑤④③②①
6. Result 2 ⑤④③②① ⑤④③②① ⑤④③②①
PERCENTAGE = (80%)
B. LAB REPORT ASSESSMENT
Discussions
Conclusion
PERCENTAGE = (20%)
Total = (A+B =100%)
2. * GENERIC SKILL ASSESSMENT (GSA) – 5%
A. Foster Good Relationship ⑤④③②① ⑤④③②① ⑤④③②①
B. Alternate Roles ⑤④③②① ⑤④③②① ⑤④③②①
C. Respect And Accept opinions ⑤④③②① ⑤④③②① ⑤④③②①
TOTAL
Remark, * : Minimum assessed TWO (2) times
SCORE RUBRIC
5 Demonstrate complete understanding of the task. Respond to ALL requirement of task.
4 Demonstrate considerable understanding of the task. All requirement of task are included
3 Demonstrate partial understanding of the task. Most requirements of task are included.
2 Demonstrate little understanding of the task. Many requirements of task are included.
1 Demonstrate a significant error of the task. No response/task not attempted
