Department of Electrical and Computer

Engineering

University of Canterbury

ENEL 203: Principles of Electronics

Electronics Laboratory Formal Report

Title of Experiment (Lab X)

by

R.A.M Drysdale

Lab partner: E.W.E. Romney

Laboratory performed on put date of lab here

Report submitted on put submission date here

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Abstract

This should be one paragraph, usually no more than 100 words, explaining what is

contained in the report. This is sometimes called an Executive Summary, and as such it

should cover all the subjects, major and minor, about which new and/or important

information is given. It should be adequate as an index and a summary, giving the

conclusions and all results of general interest in the report. Often it is only the

abstracts of research papers and reports that are widely distributed; interested readers

will access the full report if they require detailed information.

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Table of Contents

1. Introduction ........................................................................................ 1

2. Background ....................................................................................... 2

3. Experimental Results ......................................................................... 3

3.1 Figures ........................................................................................ 3

3.2 Tables ......................................................................................... 4

4. Discussion ......................................................................................... 5

5. Conclusion ......................................................................................... 6

6. References ........................................................................................ 7

Appendix ............................................................................................ 8

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1. Introduction

Start the proper page numbering from here, with the previous material (Abstract and Table

of Contents) getting lower case Roman numeral page numbers if you wish. Use the library

and textbooks to find out more about the subject, and give the reader a brief overview.

Whenever you use information from a book or journal (including figures) provide the

reader with the reference using a numbered list. For example, in a report about diodes you

might write: “As shown by Boylestad and Nashelsky [1] the current-voltage characteristics

for an ideal pn junction diode are …” or “Applications for semiconductor diodes include

detectors for THz frequency radiation [2], …”.

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2. Background

Set out the important principles of the subject(s) that you are going to describe. Make sure

that you discuss applications to put your work in the proper context. Do not simply copy

figures or formulae from the lab sheet or text books, explain them. Do not give detailed

derivations; refer the reader to textbooks for these. Only present the theory that is relevant

to the material that follows.

When you want to use an equation, this must be put onto a separate line (centred), and must

be numbered (with the equation number right justified). All symbols used in the equation

must be fully described in the text. For example, Ohm’s law can be used to determine the

current I flowing in a resistor,

R

VI = , (1)

where V is the voltage across the resistor and R is its resistance. Note that even though the

equation has its own line (to make the document easy to read) it is still part of a sentence,

so usual rules of grammar and punctuation apply.

When you want to refer the reader back to an equation later in your report, you must use

explicit referencing. For example, Eq. 1 can be rearranged to determine the voltage across

a resistor, V = IR. Note that in this case the equation is simple enough that it doesn’t need

to be separated onto its own line (an exception), and that all quantities have been defined

previously so they don’t need to be redefined here.

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3. Experimental Results

Explain the results you obtained and how you obtained them; don’t just copy the

instruction sheet. Summarise wherever possible with figures and tables, as discussed in

Sections 3.1 and 3.2. If you are going to give calculations miss out the intermediate step(s)

if not essential for understanding (assume that the reader can use a calculator to check you

results if s/he wants to).

Use sub-sections to separate topics within your report, making it easy for the reader to get

an idea of the logical structure of the work you have performed. Each section and

subsection needs an introductory paragraph, as well as a concluding paragraph in which the

main points are summarised and briefly discussed. The Discussion section that comes after

the Experimental Results should be used for putting the different sub-sections into context,

and showing how the different sets of results relate to each other.

3.1 Figures

Figures and diagrams should tell a self-contained story and should always have a title.

Figures, diagrams, graphs, flow charts etc. should all be referred to as ‘Figures’. Number

these sequentially and always refer to them in the text close to where you refer to them (but

usually after their first reference in the text), such as “As shown in Fig. 3 …” or “Figure 3

shows …”. Did you spot the difference? Use ‘Figure’ if the sentence starts with a

reference to the figure, and abbreviate it to ‘Fig.’ if the reference appears mid sentence.

The same rule applied to equations (‘Equation’ and ‘Eq.’) but not to tables (always

‘Table’).

Use different symbols for different curves on the same graph, and show error bars if this is

appropriate. For example, Fig. 1 shows measured current-voltage characteristics for two

resistors. Resistor R1 (solid line) has a nominal resistance of 470 Ω and resistor R2 (dashed

line) has a nominal resistance of 150 Ω. Each resistor value has a 10% tolerance.

4

0

10

20

30

40

50

60

70

0 2 4 6 8 10

R1

R2

I R (mA)

VR (V)

Figure 1. Current IR versus voltage VR measured for resistors R1 and R2 over

the voltage range 0–10 V.

The measured data shown in Fig. 1 has been fitted using Eq. 1 to allow the actual resistance

to be determined for each device. The results are R1 = 457±8 Ω and R2 = 155±1 Ω.

Neither value agrees with the nominal value within experimental error, however once the

10% tolerance for the nominal value of each resistor is taken into account there is good

agreement.

3.2 Tables

Use a table for summarising a large amount of numerical data, or for summarising the

values for different parameters used in an experiment or simulation (such as the component

values in a circuit). For example, the current-voltage measurements shown in Fig. 1 were

repeated for a set of 8 resistors (including R1 and R2 that have already been described) with

nominal values from 10 Ω up to 8.2 kΩ, and the results are summarised in Table 1.

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Resistor Nominal

Value (Ω)

Tolerance

(%)

Experimental

Value (Ω)

Experimental

Error (Ω)

R1 470 10 457 8

R2 150 10 155 1

R3 10 10 12.1 0.5

R4 1800 10 1680 20

R5 82 10 91 2

R6 270 5 269 5

R7 8200 5 8250 50

R8 1200 5 870 10

Table 1. Measured resistances for a set of eight resistors with nominal values

from 10 Ω to 8.2 kΩ. Tolerances on the nominal values and experimental

errors are also tabulated.

The experimental values agree with the nominal value (including the tolerance) in all but

two cases. For resistor R3 the measured value of 12.1±0.5 Ω is larger than the nominal

value, which is attributed to additional series resistance in the measurement circuit.

Additional measurements were performed with a short circuit in place of the resistor,

which showed series resistance of 0.8±0.2 Ω in the measurement circuit. Subtracting this

from the measured value for resistor R3 brings it into agreement with its nominal value.

Resistor R8 has a measured value that is significantly smaller than its nominal value, and

this discrepancy cannot be accounted for by experimental errors. The cause of this

disagreement is not clear, however it is suspected that the resistor colour code bars were

incorrectly read in this case, and the actual device that was measured was not a 1200 Ω

resistor. Further measurements would be required to correct this situation.

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4. Discussion

Relate the results to theory and explain what is going on. What are the differences between

theory and experiment and what are their causes? How error prone are your results?

Relate the results back to the applications that you mentioned in the introduction and

background.

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5. Conclusions

Emphasise the one or two main points of the report. These should be the “take-home

messages” that you want to leave the reader with. Mentally precede each statement with the

words [I conclude that…] as this will ensure that your statements are actually conclusions

not discussion or recommendations.

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6. References

[1] Boylestad, R. and Nashelsky, L. “Electronic Devices and Circuit Theory”, 6th

Edition, Prentice-Hall, Englewood Cliffs, New Jersey, 1996, pp. 10-14.

[2] Crowe, T.W. et al., “GaAs Schottky Diodes for THz Mixing Applications”, Proc.

IEEE, vol. 80, no. 11, November 1992, pp. 1827-1841.

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Appendix

Do not use an appendix unless absolutely necessary. Use only for supplementary material

that should be included, but if included in the appropriate section, would disrupt the

argument.