Summer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS EECS 100/43 Lab 5 – Nonlinear Op-Amp Circuits 1. Objective In this lab, you will learn about how to build oscillator circuits. 2. Equipment a. Breadboard b. Wire cutters c. Wires d. Oscilloscope e. Function Generator f. Power supply g. 1k resistor x 2 h. 10k resistor x 2 i. 8.2 mH inductor i. LMC6482 op-amp j. Various connectors for power supply, function generator and oscilloscope. 3. Theory a. Circuit Figure 1 shows the circuit that you will build in this lab. To get the 5k resistors, use two 10k resistors in parallel. You will build the circuit in lab, so MAKE SURE THAT YOU FINISH YOUR PRELAB BEFORE COMING TO LAB! Figure 2 has the LMC6482 pinout for reference. Figure 1. Inductor based op-amp oscillatorSummer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS Figure 2. Page 1 from the LMC6482 datasheet Derive the driving point plot for the circuit shown in figure 1 (task 1 of your prelab). Build and simulate the circuit in MultiSim (task 2 of your prelab).Summer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS b. LABVIEW scope capture You will use LABVIEW to printout a screenshot of your oscilloscope waveform and attach it to your lab report. Go through the “Getting Started with LABVIEW” document available on the EE100 homepage under handouts. You don’t have to master LABVIEW inside-out. Just get an idea of what the program does. Here are the steps for printing the scope screen using LABVIEW: 1. Download the HP54645 library from the EE100 lab homepage. There is a VI link next to Lab 5 under Lab Documents on the EE100 lab homepage. Download this VI to your U:\ network drive. NOTE: IF YOU SAVE ANYTHING ON YOUR DESKTOP, IT WILL BE ERASED ONCE YOU LOG OFF! 2. LABVIEW communicates with your instruments using the GPIB bus (General Purpose Input Output bus). The first thing you need to do is figure out the address of your oscilloscope on the GPIB bus. To do this: a. Turn on the oscilloscope b. Double click on the Measurement and Automation (MAX) icon on your desktop. Figure 3 will pop up. Figure 3. MAX main window c. Left-Click on the “+” next to d. Left-Click on . Figure 4 will pop up.Summer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS Figure 4. GPIB instrument addresses e. Depending on the number of instruments you have switched on, MAX will display their addresses. Left-Click to make sure the address displayed by MAX is correct. NOTE DOWN THE ADDRESS OF YOUR OSCILLOSCOPE – THE HEWLETT-PACKARD, 54645D. f. Close MAX. 3. Select Start → Programs → National Instruments → LabVIEW 8.2 → LabVIEW to start LABVIEW. Figure 5 will pop up.Summer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS Figure 5. LabVIEW startup screen 4. Left-Click 5. Navigate to the HP54645 folder you downloaded. Double-click on the folder and double click on the Hp54645 library. 6. Left-Click on and then Left-Click OK. Figure 6 should pop up.Summer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS Figure 6. LABVIEW scope interface 7. MAKE SURE THAT THE CORRECT GPIB ADDRESS APPEARS UNDER RESOURCE NAME ON YOUR VI. 8. MAKE SURE YOUR CIRCUIT IS POWERED UP AND SCOPE PROBE A1 IS CONNECTED TO YOUR CIRCUIT. In this case, connect probe A1 to the output of your op-amp. 9. Left-Click the Run icon. LABVIEW will capture the scope data. 10. To print the screen, Left-Click File and then Left-Click Print. 11. You can keep the defaults (Left-Click to go through the screens). Once you get to the Page Setup screen (figure 7), Left-Click to make sure that the output is what you want. 12. On the last screen, Left-Click to send output to the 140 Cory printer. TURN IN A COPY OF YOUR SCREEN SHOT WITH YOUR LAB REPORT.Summer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS Figure 7. LABVIEW page setup screenSummer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS 4. PRELAB NAME:__________________________________/SECTION____ Please turn in INDIVIDUAL COPIES of the prelab. They are due 10 MINUTES after start of lab, NO EXCEPTIONS! a. TASK 1: Draw the driving point plot below for the circuit given in figure 1. Justify your driving point plot by showing the derivation. b. TASK 2: Build and simulate the circuit in figure 1 from MultiSim. c. TASK 3: Go through the “Getting Started with LABVIEW” document available on the EE100 homepage (under handouts). PRELAB COMPLETE: _________________________________ (TA CHECKOFF)Summer 2007 Lab 5 EE100/EE43 University of California, Berkeley Department of EECS 5. REPORT NAME(S):__________________________________/SECTION____ a. TASK 1: Build the circuit from prelab task 2 on the breadboard. Use the oscilloscope cursor keys to measure the frequency of oscillation, record it in table 1 and compare to the theory and simulation. Parameter Theory Simulation Experiment % error Frequency Table 1. Frequency measurements b. TASK 2: Printout a screenshot of your LABVIEW scope vi and attach it to your lab report (refer to the Theory section, part (b) LABVIEW scope capture for instructions). TURN IN ONE REPORT PER GROUP AT THE END OF YOUR LAB SESSION. THERE IS NO TAKE HOME REPORT. 6. REVISION HISTORY Date/Author Revision Comments Spring 2007/Bharathwaj Muthuswamy Typed up source documentation, organized lab report, typed up
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