EET 220 - Digital Electronics
Experiment 2
Logic Trainer & Oscope Familiarization 2
Objectives:
To become familiar with the Logic trainer
To perform AC Measurements on Signal Sources
Discussion:
The digital Logic trainer used in this lab includes a number of features which has
already been introduced in the previous Lab. In this lab, you will investigate some of
these features and measure output levels from the AC sources present.
Procedure:
1. Signal Generators and Measurement of Logic Levels
The Logic trainer includes a variety of signal sources for use with digital and analog circuitry.
The function generator is widely used in most experiments and will serve as an introduction
both to the trainer features and to logic level waveforms.
In this Lab, and for the rest of this semester, we will not use the function generator of the
Trainer. Always, use RIGOL DG1022 to generate any signal, or the function generator
embedded with Lab-Volt 1247.
Use the function generator to generate a Digital Signal that is characterized by the following:
•
•
•
1.1)
Square Wave, at 100Hz
Low level is at Zero Volt. (Hint: use either the offset or ‘HiLevel’ and
‘LoLevel’ features on the function generator)
High level is at 5 Vdc.
Show above signal on the Oscope screen, with statistics showing Vmax, Vmin,
and Frequency. Then, get a picture of the Oscope screen and include it in this
report.
Note: make sure the coupling settings of the Oscope is DC, not AC.
The output labeled CLOCK in this panel is used to provide a logic level pulse that is
independent of the Amplitude and Offset control setting knobs on the function
generator.
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EET 220 - Digital Electronics
1.2)
From the trainer module, connect the ‘CLK’ signal to the Oscope. Make sure
the signal is at 100Hz.
Make both signal from part (1.1) and (1.2) appears on the Oscope screen. Then,
show their Vmax and their frequencies. Then, take a picture of the Oscope screen
and attach it to this report.
Note: To change the left menu of the Oscope to switch from Ch.1 to Ch.2 follow
below steps:
➢ Press the ‘intensity’ knob.
➢ In the right menu of Oscope screen, you should see ‘source’. If you
change this source to Ch.3, for instance, the statistic on the left menu will
be assigned to Ch.3.
Note: to display some statistics about the signal in the lower portion of the
Oscope screen, follow underneath steps:
➢ Make sure the ‘source’ is set to the desired signal
➢ To display any statistics related to the vertical parameters of the signal
such as the Vpp or Vmax, press the ‘menu’ button located on the upper
left corner of the Oscope. If you press it, the upper-left part of the screen
displays either ‘horizontal’ or ‘vertical’. Keep pressing the ‘menu’ button
until it displays ‘vertical’.
o There are two buttons located at the lower-left side of the Oscope
and they have an arrow signs. If you click on them, they will select
the desired statistics on the Oscope screen. Keep pressing them
until you stop on the parameter you want to display. Then, press
the corresponding button and it will display it for you.
➢ To display any statistics related to the horizontal parameters of the signal
such as the frequency or the period, press the ‘menu’ button located on
the upper left corner of the Oscope. If you press it, the upper-left part of
the screen displays either ‘horizontal’ or ‘vertical’. Keep pressing the
‘menu’ button until it displays ‘horizontal’.
o There are two buttons located at the lower-left side of the Oscope
and they have an arrow signs. If you click on them, they will select
the desired statistics on the Oscope screen. Keep pressing them
until you stop on the parameter you want to display. Then, press
the corresponding button and it will display it for you.
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EET 220 - Digital Electronics
2. From the previous, part.1, calculate the FREQUENCY of the clock waveform by
counting the number of grid marks on the scope display horizontally: You must count
from one rising edge of the waveform to the next rising edge.
Note: to change the time scale on the Oscope, turn the knob labelled with ‘scale’
located on the bottom-right side of the Oscope. You might see two knobs
labelled with ‘scale’ mark, but we are concerned only with the knob that belongs
to the ‘horizontal’ group. While you are turning the knob, the scale changes on
the display screen on the top-left corner.
Calculate the frequency using underneath formula.
➢ Total number of the squares enclosed between two rising edges : ( __ )
➢ The horizontal scale on the Oscope in second: (____)
➢ Calculate the period of one cycle using the formula:
𝑃𝑒𝑟𝑖𝑜𝑑 (𝑇)𝑖𝑛 𝑠𝑒𝑐𝑜𝑛𝑑𝑠 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑞𝑢𝑎𝑟𝑒𝑠 × 𝑂𝑠𝑐𝑜𝑝𝑒 ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝑠𝑐𝑎𝑙𝑒 𝑖𝑛 𝑠𝑒𝑐.
➢ Calculate the frequency of the signal using underneath formula:
𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 (𝑓) 𝑖𝑛 𝐻𝑧 =
1
𝑇
➢ Compare the calculated frequency with the frequency shown on the Oscope.
Are they equal? Not equal? Comment on the result and include the
calculation process in the report.
3. Adjust the frequency on the Trainer to become 200Hz. Then, repeat Part.2
4. From the previous, part.1, calculate Vpp of the function generator waveform by
counting the number of grid marks on the scope display vertically: You must count
from the lower end to the highest end the waveform.
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EET 220 - Digital Electronics
Note: to change the ampltiude scale on the Oscope, turn the knob labelled with
‘scale’ located on the bottom-right side of the Oscope. You might see two knobs
labelled with ‘scale’ mark, but we are concerned only with the knob that belongs
to the ‘vertical’ group. While you are turning the knob, the scale changes on the
display screen on the bottom-left corner.
Unlike the time scale, the vertical scale can be customized to each channel
input: for instance, if you are displaying two channels on the Oscope screen, it
will display two vertical scales.
To control the vertical scale of a specific channel, simply, press the
corresponding ‘CHx’ button once. Then, on the Oscope screen, the associated
vertical scale on the lower-left side will be highlighted.
Calculate the Vpp using underneath formula.
➢ Total number of the squares enclosed between highest and lower edges : (
__ )
➢ The vertical scale appearing on the Oscope in volts that is associated with
function generator signal: (____)
➢ Calculate the Vpp using the formula:
𝑉𝑝𝑝 𝑖𝑛 𝑣𝑜𝑙𝑡𝑠 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑞𝑢𝑎𝑟𝑒𝑠 × 𝑂𝑠𝑐𝑜𝑝𝑒 𝑣𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑠𝑐𝑎𝑙𝑒 𝑖𝑛 𝑣𝑜𝑙𝑡𝑠
➢ Compare the calculated Vpp with the Vpp shown on the Oscope. Are they
equal? Not equal? Comment on the result and include the calculation
process in the report.
5. Adjust voltage on the function generator such that it becomes as follow:
•
•
•
Square Wave, at 100Hz
Low level is at Zero Volt. (Hint: use either the offset or ‘HiLevel’ and
‘LoLevel’ features on the function generator)
High level is at 7 Vdc.
Repeat part 4.
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