Experiment 3: Digital Oscilloscope Familiarity

Transcription

1 aboratory xperiment 3 rev 1 xperiment 3: Digital Oscilloscope amiliarity Objectives: Today's experiment builds on any previous oscilloscope experiences you may have had. Digital oscilloscopes are popular today for a variety of good reasons, not the least of which is their ability to hold and display data associated with either a periodic or one-time event. Pre ab: ead and understand Hambley Section 5.1 Determine the V Peak and V Peak-Peak of a 120 V MS signal Part : Oscilloscope unctional heck Procedure: 1. Open to page 5 of the TDS-210 User Manual (red cover), turn the scope ON (top left), and allow time for the self test to complete (about 5 seconds). 2. onnect a probe to H-1 and make the test contacts described on page 5 of the user manual (we only will test H-1 today). 3. Push UTOST button and validate the probe. f the square wave is imperfect, contact your lab instructor. efer to page 6 of the user manual for information on probe compensation. 4. Select the H-1 Menu button (left at center). description of the display screen area is available on page 10 of the User Manual. ecord on the Data Sheet the following data read from the bottom of the display screen: H-1 volts per division (tem 11) Horizontal Time ase in seconds per division (tem 10) Probe amplification (if not 10, toggle until it is) Warning: Whenever using the probes, verify that the 10 magnification is selected. 5. Select the MSU button (top center) and toggle the upper submenu until Source = H-1 (submenus are vertically stacked). Toggle again for Type and record on the Data Sheet: H-1 requency H-1 Period H-1 Mean H-1 Pk-Pk Note: The H-1 Pk-Pk value (VPP) provides the absolute difference between the maximum and minimum peaks of the entire waveform. This value is not necessarily representative of the steady state peak amplitude, so it should be interpreted sensibly. 6. Open the User Manual to page 20 so you follow along as you select the QU button (top right), viewing the display in several modes using the submenu buttons. or each mode, note the effects of toggling /STOP button (top right). Describe in your lab report your observations and the differences between the acquire modes: Sample, Peak Detect, verage, and verages. Page 1 of 7.M. aurie, G.. rcher

2 aboratory xperiment 3 rev 1 Part : Waveform Generator Procedure: 1. Power up the HP waveform generator. 2. Develop experience setting the output frequency. Many options are available, such as: Q ~ NUM > khz ---> khz Describe in your lab report the function of the arrow keys for this step. 3. Now rotate the knob a few clicks: Try these combinations: ----> khz ----> 7.670kHz NUM > MHz NUM > kHz Describe in your lab report the function of the arrow keys for this step. n the future, set frequencies as you best see fit. 4. Now practice setting output amplitudes. MP NUM > M VU ----> 10 VPP or 20 VPP (either is acceptable) xplain in your lab report what happened? NUM 110 SHT ----> 110 mv MS ~ Describe in your lab report the effect SHT had on the units display? Page 2 of 7.M. aurie, G.. rcher

3 aboratory xperiment 3 rev 1 5. Next select the square wave button,, followed by SHT ----> D: SYS MNU (as needed) ----> HGH Z ----> TNG 6. Using any method, set: NOT: We should take this step whenever our circuit has an impedance exceeding several hundred Ohms. MP 200 mv PP Q khz Part : Signal Measurements Procedure: 1. or this part you will use the HP33120 waveform generator as an Voltage Source. Use any method described in Part to set the HP33120 for a sinusoidal output ~ with amplitude 1.2 V MS and frequency of 60Hz. This signal is a scaled down representative of standard power available at most household outlets, which has an amplitude of 120 V MS at a frequency of 60Hz 2. onfigure the luke 45 as an Ohmmeter and measure the resistance of the 1000Ω resistor. ecord this value in the data sheet. 3. You will use the luke 45 as an Voltmeter by pushing the V~ button. ll readings will now be in V MS. 4. onfigure the eithley multimeter as an mmeter by pushing the button in and set the meter to uto ange. 5. onstruct the circuit described by igure 1. Do Not connect the positive lead of the HP33120 until you have verified the other circuit connections are wired correctly. Make certain that the mmeter is connected in SS and the Voltmeter is connected in P. Note the common ground connection is simply one conductive path referenced at zero volts. Use banana leads to connect the components, but 10 probes to measure the voltage directly across the 1000Ω resistor. n connecting the probes, use common sense precautions to avoid breaking the delicate arms. lligator clips from probes must be connected to the common ground. 6. ecord values on the data sheet for Volts and urrent measured with the multimeters. Page 3 of 7.M. aurie, G.. rcher

4 HU/MU N % UTZTON T 2 U 3 0 V Ẉ T PNT HP PH SHT N HU/MU N N 8 T 2 U3 % UTZTON T PNT HP PH SHT N HU/MU N T 2 U 3 % UTZTON T PNT HP N PH SHT HU/MU N N 8 T 2 U3 % UTZTON T PNT HP PH SHT N aboratory xperiment 3 rev 1 igure 1 7. Push UTOST to generate a display. f the display is excessively noisy, the problem is usually sloppy leads, so try to remedy these first. f changing leads doesn't correct a problem, ask for help. Verify you are using 10 probe settings (HNN MNU buttons). xperiment with the volts per division and seconds per division knobs on the oscilloscope to properly display the voltage waveform. djust the waveform position using the position knobs. ecord values on the data sheet for the H1 volts per division and seconds per division. 8. Push the MSU button of the oscilloscope and repeatedly the H1 softkey. ecord measured values on the data sheet values for requency, Period, V Mean, V P-P, and V MS. Describe in your lab report your observations and comment on whether these values agree with what is expected. 9. econfigure the circuit as shown in igure 2 by replacing the 1000Ω resistor with a 4.7µ capacitor in series with a 6.8Ω resistor. onnect the 10 H1 Probe to the mmeter side of the 6.8Ω resistor and the the 10 H2 Probe to the 4.7µ capacitor. oth alligator clips of the 10 probes should be connected to the ground side of the 4.7µ capacitor. 10. Push UTOST to generate a display. f the display is excessively noisy, the problem is usually sloppy leads, so try to remedy these first. f changing leads doesn't correct a problem, ask for help. Verify both channels are using 10 probe settings (HNN MNU buttons). xperiment with the volts per division and seconds per division knobs on the oscilloscope to properly display the voltage waveform. 11. Go to the P and start the WaveStar pplication. This Program allows you to acquire the display of the digital oscilloscope. Print your display and include it with your lab report. Describe in your lab report your observations and comment on whether these values agree with what is expected. What are the observed phase angle and frequency differences between H1 and H2? 12. sk your lab instructor to verify your results. Then disconnect your equipment and neatly return items to their original locations. Page 4 of 7.M. aurie, G.. rcher

5 HU/MU N % UTZTON T 2 U 3 0 V Ẉ T PNT HP PH SHT N HU/MU N N 8 T 2 U3 % UTZTON T PNT HP PH SHT N HU/MU N G D T 2 U 3 % UTZTON T PNT HP N PH SHT HU/MU N N 8 G D T 2 U 3 % UTZTON T PNT HP PH SHT N aboratory xperiment 3 rev 1 igure 2 gilent unction Generator eithly 2000 mmeter 6.8 k Tektronix TDS luke 45 Voltmeter Page 5 of 7.M. aurie, G.. rcher

6 aboratory xperiment 3 rev 1 Prelab: Data Sheet V Peak V Peak-Peak Part : Oscilloscope unctional heck H-1 volts per division Horizontal seconds per division Probe amplification (if not 10, toggle until it is). H-1 requency H-1 Period H-1 Mean H-1 P-P Part : Signal Measurements Measured esistance Measured Voltage Measured urrent requency Period V Mean V P-P V MS Your Name Partner Name ab nstructor Date Page 6 of 7.M. aurie, G.. rcher

7 aboratory xperiment 3 rev 1 Discussion guide for xperiment 3 Part : Proc. 6: Describe your observations and compare the difference between the acquire modes: Sample: Peak Detect: verage: verages: Part : Proc. 2, 3: Describe the function of the arrow keys when seting the output frequency., : <, >: Proc. 4: Show the result when setting the output amplitudes using the following keys, and explain why. nter number 110 : why? nter number 110 shift : nter number 110 shift : Describe the effect SHT had on the units display. nter number 110, explain why the result is 7.07/3.53 VMS? Part : Proc. 7: ecord values for the H1 volts per division and seconds per division. volt/div: sec/div: Proc.8: Describe your observations and comment on whether these values agree with what you expected. Proc. 11: Print the display acquired from the oscilloscope. Describe your observations and comment on whether these values agree with what you expected. Phase angle difference between H1 and H2: requency difference between H1 and H2: omments: Page 7 of 7.M. aurie, G.. rcher