Laboratory Procedures DeVry University College of Engineering and Information Sciences
I. OBJECTIVES
1. Use a function generator to produce different periodic waveforms.
2. Use an oscilloscope to observe periodic waveforms.
3. Use the oscilloscope to measure the waveform properties, including:
a. Frequency, f and Time period, T
b. Amplitude or Peak Value, VP , and Peak to Peak Value, VPP
c. RMS Value, VRMS
4. Repeat the measurements using MultiSim
II. PARTS LIST
Function generator
Dual channel oscilloscope
BNC to BNC cable (50 Ω)
BNC cable with split ends on one side, or banana plugs
DMM (digital multimeter)
IBM PC or compatible with MultiSim software
III. PROCEDURE
A. Observing Waveforms on the Oscilloscope
1. Connect the function generator output to Channel 1 of the oscilloscope with a BNC-BNC cable as shown in Figure 1 below and turn on both instruments.
Figure 1: Function Generator to Oscilloscope Connection
2. Select the Sine wave button of the function generator. Set the frequency to 1 kHz.
3. Select the Amplitude button on the function generator to set the output voltage. Adjust the voltage to 2 V peak to peak.
4. On the oscilloscope, set the Volts/Div knob to 500 mV/Div. Adjust the time base control to 500 µs/Div.
5. On the oscilloscope, select the AC coupling, select the EDGE button in the trigger area, and select positive. Make sure that Source 1 is selected.
6. The output waveform as seen on the oscilloscope is shown in Figure 2 below:
Figure 2: Sine Waves Displayed on Oscilloscope Screen
7. Using the oscilloscope, including the cursors and built-in functions, and the DMM (where indicated), record the required measurement into Table 1.
Frequency
(kHz)
Peak Value
(VP, in V)
Peak to Peak Voltage, VPP
RMS Value, VRMS
Voltage as per DMM
Time period (msec)
Table 1: Sine Wave Measurements
8. Calculate the time period of the sine wave.
T = ________________________
9. Compare with the measurement done on the oscilloscope. Verify whether both numbers agree or not.
YES_____ NO______
10. Change the sine wave frequency only on the function generator as specified in Table 2. Measure the time period and the RMS values for each setting and compare the measurement with your calculations.
Frequency, (kHz)
Time Period
RMS Value
Measured
Calculated
Measured
Calculated
2.0
3.0
4.0
5.0
Table 2: Different Sine Wave Frequency Parameters
11. Change the wave form shape only on the function generator to different types as shown in Table 3 and take measurements of the corresponding RMS values in each case. You may choose any frequency from the above table of measurements. Explore the Internet to obtain the RMS value of different (standard) waveforms and record the values in the table below:
Type of Waveform
Measured Frequency
RMS Value from Internet
Value per DMM
Square Wave
Triangle Wave
Table 3: RMS Values for Different Waveforms
B. Computer Simulation of the Experiment.
1. Repeat the measurements using MultiSim. Use the simulation circuit shown below.
Figure 3: MultiSim Simulation Circuit
Notice that Function generator, XFG1 is a generic type and XSC1 is an Agilent oscilloscope.
2. Double click on the XFG1 to select the waveform type, the frequency, and the amplitude as shown in Figure 4.
Figure 4: MultiSim Function Generator Operation
3. Use the simulated circuit to repeat the measurement made in completing Tables 2 and 3. Record the results in Table 4.
Type of Waveform
Measured RMS Results (Tables 2 & 3)
MultiSim Simulation Results
Sine Wave
Square Wave
Triangle Wave
Table 4: MultiSim Measurement for Various Waveforms
IV. TROUBLESHOOTING
Describe any problems encountered and how those problems were solved.
Ch1Ch2
Function GeneratorDual Channel Oscilloscope
OUT
BNC -BNC Cable
Ch1
Ch2
Function Generator
Dual Channel Oscilloscope
OUT
BNC - BNC Cable