ELTRY251
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Name:
Lab 01
Electronics (AC)
Introduction
In this experiment, you will learn the basic concept of Alternating Current (AC) and
the operation of a Function Generator and Oscilloscope. You will also learn how to
measure the frequency of a sinusoidal waveform with an oscilloscope.
Function Generator is basically an AC voltage source which is capable of producing
Sine, Square, and Triangle waveforms. The output magnitude and frequency is
adjustable.
Oscilloscope is a device that shows a representation of voltage vs. time. With an
oscilloscope you can visually inspect the waveform and measure the voltage, period
and frequency.
Equipment
1.
2.
3.
4.
Function Generator
Digital Multi-meter (Fluke 87)
Oscilloscope
Alligator – alligator wires
Procedure
1. Turn on the Oscilloscope and wait few seconds for the display
2. Set the scope controls as following. Note: Following setting might be different
for different brand of scope. This setting is to make sure you will see a
straight line in the middle of the display. If after power up you see the
straight line, skip this setting.
Scope Controls
Trigger Source
Trigger Slope
Trigger Coupling
Time/Cm
Volt/Cm
AC/DC
Vertical Mode
Intensity
Focus
Vertical Position
Horizontal Position
Setting
Channel 1
+
AC
0.5 ms (Calibrated)
1 V (Calibrated, Pushed in)
AC
Channel 1
Mid-position
Mid-position
Mid-position
Mid-position (Pushed in)
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ELTRY251
Please Print
Lab 01
Name:
Electronics (AC)
3. Connect the Function Generator to the DMM and scope as shown below.
Scope
Function Generator
O O O
O O O
+
V
GND
O O O
Ch2
Ch1
Sin
Sqr O
Tri
GND
Out
8 8 8 8
O
O
O
O
O
O
-
Volt Meter
4. Set the voltmeter to measure AC Voltage.
5. Turn on the function generator and set it as following. Note the frequency setting
is approximate and voltage reading is via DMM and is RMS.
Fun. Gen.
Controls
Setting
Output
Sine Wave
Magnitude
5 V (RMS)
Frequency
5000 Hz
6. Adjust the scope to observe a stable sine wave.
7. Read the frequency form the function generator and the voltage (RMS) from the
DMM and record it in the following table.
Function Generator
DMM
Frequency (Hz)
RMS (V)
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ELTRY251
Please Print
Lab 01
Name:
Electronics (AC)
8. Read the scope and record it in the following table.
Oscilloscope Measurement
# Horz. Time /
# Vert.
Volts /
div.
Div.
Div
Div
Period
(Sec)
Freq
(Hz)
Calculation
VPP
VP
(V)
(V)
VRMS
(V)
9. Calculate the Period, Frequency, VPP, VP, and VRMS and record it in the above
table.
Period (T) = (# Horizontal Divisions) * (Time / Div)
Freq = 1 / T
VPP = (# Vertical Divisions) * (Volts / Div)
VP = VPP / 2
VRMS = 0.707 * VP
10. Draw an exact representation of what you see on the scope.
11. Change the output of the function generator to square wave.
12. Change the output of the function generator to triangle wave.
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ELTRY251
Please Print
Lab 01
Name:
Electronics (AC)
13. Describe your observation.
14. Change the output of the function generator back to sine wave.
15. Adjust the frequency and magnitude of the function generator according to the
following table.
16. Adjust the scope for best visual inspection for each setting and complete the
following table.
Func.
Gen
DMM
Freq
(Hz)
RMS
(V)
10
KHz
15
KHz
25
KHz
50
KHz
Measured Oscilloscope
#
Horiz
Div
Time /
Div.
#
Vert
Div
Volts /
Div
Calculated
T
(Sec)
Freq
(Hz)
VPP
(V)
VP
(V)
1V
2V
2.5 V
3V
Conclusion
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VRMS
(V)