Sehir - EE 312 - Fall 2017
Introduction to Communication Systems
Lab 1 manual
Basic Lab Instruments
Prepared by:
Ilkin Safarli
Supervisor:
Dr. Kemal Ozdemir
• Preliminary work is due just before the lab and Final Report is due a week after
the lab session.
• Preliminary and Final reports are all to be performed individually.
Sehir - EE 312
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Lab 1 - Page 2 of 5
October, 2017
Objective
The focus of Lab 1 is to get familiar with digital multimeter, function generator, and
oscilloscope. We will construct simple electronic circuits and analyze the behavior of
these circuits by using the basic equipment listed above.
2
Preliminary Work
All answers must be clear and straight to the point (concise). You are required to
explain your answers in your own words. Plagiarism will lead to point deduction.
Before the lab do research on the followings:
(a) What is the operating principle of voltmeters and ammeters?
(b) What is the function of function generator?
(c) What are the functions of oscilloscope and multimeter? How are multimeters
different from oscilloscopes?
Before the lab complete the following tasks:
(d) Build the circuit in Figure 2 by using Cadence1 and run simulation (transient
response for 5 ms). Attach screenshot of your circuit. 2
(e) Plot Out 1 and Out 2 in Figure 2 by using Cadence. Attach the figures to preliminary work.
1
You can use any circuit simulator such a Cadence, Multisim, Partsim, etc. This simulator can
be used online, and is free and simple to use, but requires registration:
https://easyeda.com
2 If you are unfamiliar with circuit simulation, you are required to use one of the numerous
online resources to learn the basic circuit simulation techniques. There are a number of videos
on using EasyEDA on Youtube.
Sehir - EE 312
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3.1
Lab 1 - Page 3 of 5
October, 2017
Procedure and Analysis
Digital Multimeter
Digital Multimeter can measure voltage, current, and resistance. Remember that
voltage measurements are taken in parallel while current measurements are taken in
series.
3.1.1
Exercise: measuring voltage and current
Build the circuit in Figure 1. Measure the voltage across R1 and current through R2.
Calculate the theoretical values and in your report compare them with the
measured values.
Figure 1: Resistive Network
3.2
Function Generator
The function generator generates sine waves, square waves and triangular waves.
The waveform parameters such as duty cycle, frequency, and amplitude (peak-topeak) are set via the front panel buttons.
3.2.1
Exercise: setting parameters
Set the frequency to 5 KHz, waveform to square wave and amplitude to a random value.
Attach the output to the scope probes of oscilloscope.
3.3
Oscilloscope
Oscilloscopes are used to observe the change of an electrical signal over time. The
observed waveform can be analyzed for such properties as amplitude, frequency,
rise time, time interval, distortion and others3. Modern oscilloscopes can also do
simple math operations such as invert, add, subtract and FFT.
Sehir - EE 312
3.3.1
Lab 1 - Page 4 of 5
October, 2017
Multimeter vs Oscilloscope
We typically use multimeter for DC operations, while oscilloscope is used for time
varying signals. Digital multimeters can do very limited AC measurements (i.e. AC
and frequency) and its frequency range is very limited. On the other hand
oscilloscope cannot do much DC analysis. In short DMM is best for DC measurement
and oscilloscope for AC analysis.
3.3.2
Exercise: measuring via oscilloscope
Most properties of a signal can be measured by using the measure function of oscilloscope.
In previous exercise we attached the output of function generator to scope of oscilloscope.
Now press Measure button of oscilloscope and measure frequency and amplitude of the
signal. Take screenshots and attach them to your report.
Note: in order to take screenshots insert a USB flash drive into the front USB flash port of
oscilloscope and use Save/Recall button, or use the camera on your mobile device to capture a
clear image of the oscilloscope screen.
Another way of measuring signal properties is to use cursors. By using cursors measure
amplitude and frequency again, take screenshots and attach them to your report.
3Retrieved
3.4
from https://en.wikipedia.org/?title=Oscilloscope
Sine Wave Converter
Build the circuit in Figure 2 (for both op-amps: VS+ = 10 V, VS− = 10 V).
− Connect the scope
probes to Out 1. What is shape of the signal? Measure amplitude and frequency of the
signal. Attach screenshots to your report. Repeat the same steps for Out 2. Give a few
examples for real life use-case of this circuit.
Figure 2: sine wave converter
In your report compare simulation results with the results that you obtained in lab
and comment.
Sehir - EE 312
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Lab 1 - Page 5 of 5
October, 2017
Report Format
Your post lab report should consist of a just Results & Discussions. Answer ALL the
questions posed to you in section 3 of this manual for the discussion part, and
include all the simulation results (where you have been asked to compare results)
and the screenshots (oscilloscope measurements) from the lab experiment for the
results part. You should organize your results and discussions into subsections titled
with the experiment number (such as 3.1.1).