University of California, San Diego Department of Electrical and Computer Engineering

Transcription

1 University of California, San Diego Department of Electrical and Computer Engineering Part One: Introduction of Lab TAs ECE65, Spring 2007 Lab 0, ECE 65 Lab Orientation 1) James Liao, -4 th year undergraduate student in ECE -Undergraduate depth: digital signal processing (DSP) 2) Eldridge Alcantara, -1 st year Master of Engineering (M.Eng.) grad student in ECE -Part of the 5 year BS/MEng program -Undergraduate depth: communication theory and systems (CTS) Part Two: Lab Rules 1) Do not be late. You have until 2:15PM to make it to the lab. After 2:15, the doors will close and you will not be allowed to come in. Your name will be reported to Professor Najmabadi. You will need to come in during make-up session to perform the experiments. You will also have to turn in a separate lab report. 2) You should complete, or at least attempt to complete, all the pre-lab (both circuit analysis and PSpice simulation). Pre-lab will be checked at the beginning of the lab section. 3) No pre-lab --> No lab. You will not be allowed perform the lab experiments for the week without the pre-lab. No exceptions. Your name will be reported to Professor Najmabadi. You will need to come in during make-up session with the completed prelab before you can start the experiments. You will also need to turn in a separate lab report. 4) Lab reports are due at the beginning of the lab. They will be graded and returned approximately one week later. 5) All lab re-grade requests must be made no more than 1 week after you have received the graded lab report.

2 Part Three: Lab Schedule Tuesday 12:30-2:30 James (Open Make-up Session) Wednesday 2:00-5:00 James & Eldridge (Closed Lab Section) Thursday 2:00-5:00 James & Eldridge (Closed Lab Section) Friday 2:00-3:30 James (Open Make-up Session) 3:30-5:30 Eldridge (Open Make-up Session) Week Wednesday/Thursday Lab Section Other Notes 1 Lab Orientation TAs in PSpice Lab on Friday during make-up sessions for Lab 1 help 2 Work on Lab 1 TAs in PSpice Lab for Lab 1 Help Lab 1 due at Friday lecture 3 Pre-Lab 2 Checked Perform Lab 2 experiments 4 Lab 2 Report Due Pre-Lab 3 Checked Perform Lab 3 experiments 5 Lab 3 Report Due Pre-Lab 4 Checked Perform Lab 4 experiments 6 No Lab experiments Lab 4 Report Due Lab open for midterm questions 7 Pre-Lab 5 Checked Perform Lab 5 experiments Midterm Review Session: Sat, May 5, Date and Time TBA Midterm Week: Date TBA Lab 4 Report may be due on midterm day (subject to change) 8 Lab 5 Report Due Pre-Lab 6 Checked Perform Lab 6 experiments 9 Lab 6 Report Due Pre-Lab 7 Checked Perform Lab 7 experiments 10 Lab 7 Report Due Final Review Session: Dates and Time TBA 11 Lab Closed Finals Week Special Office Hours for Final Dates and Times TBA

3 Part Four: Introduction to the Oscilloscope and the Function Generator I. Overview of Oscilloscope Locate the following on the oscilloscope. Check them off as you locate them. Ask a TA if you cannot find a particular item a) Power b) Autoset c) Ch.1 Volts/Div d) Ch.2 Volts/Div e) Save/Recall f) Run/Stop g) Hardcopy h) Ch.1 Vertical Position i) Ch.2 Vertical Position j) Measure k) Sec/Div l) Display m) Cursor n) Acquire o) Ch.1 Menu p) Ch.2 Menu q) Horizontal Position r) 5 Unlabeled Buttons (Submenu Buttons) II. Overview of Function Generator Locate the following on the function generator. Check them off as you locate them. Ask a TA if you cannot find a particular item. a) Power b) Output Knob c) Frequency Dial d) Offset Knob e) ATT -20dB Button f) Amplitude (AMPL) knob g) 7 Multiplier Buttons (1, 10, 100, etc.) h) 3 Waveform Buttons (Square, Triangle, Sine)

4 III. Getting Started with the Oscilloscope 1) Turn on the oscilloscope 2) Resetting the oscilloscope. Before you start taking any measurements, you will need to first reset the settings on the oscilloscope to its default settings. Follow these instructions to reset the oscilloscope: a) b) c) d) e) f) 3) Changing the source channels. Next, change the source channels so that the first two readings come from Ch1. and the last two come from Ch.2. Follow these instructions: a) b) 4) Changing the measurement types. Next, change the measurement types to the following: Freq, Pk-Pk, Period, Pk-Pk. Follow these instructions: a) Source Type CH1 Freq CH1 Pk-Pk CH2 Period CH2 Pk-Pk b)

5 5) Now connect the two scope probes to the oscilloscope, one on the Ch.1 knob and the other on the Ch.2 knob. Make sure both scope probes are set to X10. CH1 CH2 X1 X10 IV. Getting Started with the Function Generator CH1 CH2 OUTPUT Long Clip Red Clip Small Black Clip Small Black Clip 1) Turn on the function generator. 2) Connect the function generator cable to the Output knob. 3) Connect the function generator cable directly to Ch.1 on the oscilloscope. 4) Push Autoset on the oscilloscope to see the generated signal on the screen. By default, the function generator is set to generate a triangle wave when it is first powered up. V. Using the Function Generator with the Oscilloscope 1) Take note of the following two measurements displayed on the oscilloscope: a) The Ch.1 Freq is 2 KHz. b) The Ch.1 Pk-Pk is 1.26 V

6 2) Peak-to-Peak vs. Amplitude. Note the difference between peak-to-peak and amplitude. Draw on the diagram below how each one is measured: 3) Changing the Amplitude. Use the AMPL knob on the function generator. AMPL a) Max peak-to-peak reading: b) Min peak-to-peak reading: 4) EXERCISE ONE: Set the function generator to a triangle wave with a 5 V amplitude. Note again the difference between amplitude and peak-to-peak. When you have that set, raise your hand to have a TA check you off. 5) Changing the frequency. Use the following on the function generator: FREQUENCY 1M 100k 10k 1k a) Use the frequency dial. Turn the dial to make small changes in frequency. b) Using the frequency dial and the multiplier buttons. Use these two to set a particular desired frequency. For example, to set the frequency to 1.2 khz, turn the dial to 1.2 and push the 1k button. How this works: 1.2 x 1k = 1.2 khz.

7 6) EXERCISE TWO: Try setting the following frequencies. Check them off as you go along. Raise your hand if you have are having trouble setting a particular frequency. Make sure to push Autoset whenever you set the signal to a new frequency so that you can see the generated signal on the screen. When you have figured out how to set all the frequencies, raise your hand to have a TA check you off. a) 2 khz b) 150 Hz c) 10 khz d) 700 khz 7) Generating different waveforms. The function generate can generate any of the following three waveforms: a square wave, a triangle wave, and a sine wave. Locate those buttons on the function generator and test it out on the oscilloscope. 8) EXERCISE THREE: Generate a sine wave with an amplitude of 4 V and a frequency of 10 khz. VI. Using the Oscilloscope 1) Set the function generator to generate a triangle wave with a frequency of 2 khz and an amplitude of 5 V. 2) Note the following items on the oscilloscope screen. Draw below the time axis. Also, mark the volts per division and seconds per division scales on the graph. 1 CH1 5.00V CH2 500mV M 250 µs

8 VOLTS / DIV SEC / DIV 3) Changing the volts per division. You can increase the volts per division by turning the Ch.1 VOLTS/DIV knob to the left. Note the changes on the screen. The volts per division goes up, and the graph is smaller. You can decrease the volts per division by turning the knob to the right. Note that your graph is bigger. If your signal goes past the length of the screen, push Autoset. 4) Changing the seconds per division. You can increase the seconds per division by turning the SEC/DIV knob to the left. Note the changes on the screen. The M value changes to 500 µs and you get more cycles per second. You can decrease the seconds per division by turning the SEC/DIV knob to the right. Here, you will get less cycles per second. If there are too many or not enough cycles displayed on the screen, push Autoset. 5) Moving the vertical position. You can move the graph up and down by using the Ch.1 Vertical Position knob (the one on the left). VERTICAL Note the reading on the display on the bottom as you move the graph: CH1 vertical position 0.88 divs (4.40V). This is telling you where the graph is centered on the main axis of the oscilloscope. 6) EXERCISE FOUR: Adjust the position of the graph so that the center of the graph is on 0.00 divs (0.00 V). Demonstrate to a TA that you know how to center the graph around zero volts. HORIZONTAL 7) Moving the horizontal position. You can move the graph left and right by using the Horizontal Position knob. Feel free to test this out. 8) Using the Cursor Function. Here are some general instructions: a) Push Cursor to change from the measure function to the cursor function. b) Notice the boxes on the screen: -Type: it can be voltage or time -Source: which channel you are measuring

9 c) Measuring voltage using cursor. Change the type to Voltage by pushing the corresponding submenu button. Change the Source to channel 1 or 2. Note the two horizontal cursors that come up. Each of the two cursors can be controlled through the vertical position knobs that you used to move the graph up and down. VERTICAL CURSOR 1 CURSOR 2 There are three important boxes to note: -Delta: the distance (absolute value) in volts between the two cursors -Cursor 1: the voltage measurement of the first cursor -Cursor 2: the voltage measurement of the second cursor d) Measuring time using cursor. Change the type to Time by pushing the corresponding subpanel button. Change the Source to channel 1 or 2. Note the change to two vertical cursors. Again, each of the two cursors can be controlled through the vertical position knobs. VERTICAL CURSOR 1 CURSOR 2 Also note the three important boxes on the screen: -Delta: the distance (absolute value) in time between the two cursors -Cursor 1: the time measurement of the first cursor -Cursor 2: the time measurement of the second cursor 11) EXERCISE FIVE: Measure the slope of the rising edge of your triangular wave using the cursor function. When you have the slope calculated, raise your hand and have it checked by a TA.