1Nodal and Mesh Analysis: Comparison of Analysis, Experimental, and Simulated (SPICE) Results ECE 2100 Circuit Analysis updated 8 October 2010 Pre-Laboratory Assignment 1. Consider the circuit of Figure 1. Find equations for node voltages V1, V2, V3, and V4 using nodal analysis. Use symbolic voltage source and resistor values, e.g. VS and R1 (not 1V and 1k) in your equations. 2. Consider the circuit of Figure 1. Find equations for mesh currents I1, I2, I3, and I4 using mesh analysis. Use symbolic voltage source and resistor values, e.g. VS and R1 (not 1V and 1k) in your equations. Figure 1. Resistive Circuit2Procedures Part One 1. Use your SPICE simulation engine to build an example circuit provided by your laboratory instructor. Conduct both a DC operating point analysis and a DC sweep simulation as instructed. Part Two 2. Reproduce the following table in your lab notebook: experimental simulated analysis % error (experimental vs. simulated) % error (experimental vs. analysis) VS V1 V2 V3 V4 I1 I2 I3 I4 3. Select seven random resistors and construct the circuit of Figure 1 without the voltage source. The values shown are examples only. 4. Measure the resistance Req “seen” by the voltage source using your ohmmeter. Select a value of VS such that 20.25SeqVR< W 5. Draw a schematic diagram of the circuit carefully showing all measured resistor values and the voltage source value. Do not touch both ends of the resistor when measuring its3resistance (why not?)! It is best to lay the resistor flat on the bench and then press the probe leads onto the resistor leads while holding only the plastic part of the probes (of course we never touch the metallic portion of the probe leads in any case, particularly for an energized circuit!). Part Three 6. Following instructions provided by your lab instructor, simulate this circuit using your SPICE engine for your computed voltage VS and measured resistor values using a DC operating point simulation. Place your simulated results in the table (“simulated” column) of the table of laboratory procedure step 2. Watch units! You may wish to save your schematic to your own memory device for later use. 7. Now perform a SPICE DC Sweep analysis. Plot VS vs. the current provided by VS. Measure the slope. Compare this value to Req as measured in laboratory procedure part 4. Should these numbers match? If your slope is negative, something is wrong (why?). Part Three 8. Connect the voltage source to the circuit and energize the circuit. Adjust VS to provide the value computed in laboratory procedure step 4. Measure and record the voltage source value VS in the table (“experimental” column) of laboratory procedure step 2. 9. Measure the node voltages and mesh currents. Place your measurements in the table (“experimental” column) of laboratory procedure step 2. Watch units! 10. Compute the percentage error for each experimental value in the “experimental vs. simulated” column of your data table. Consider the simulated values to be the reference. 11. DO NOT DISASSEMBLE YOUR CIRCUIT until your laboratory unit has been signed off as complete. Analysis 1. Using your equations from the pre-lab and your experimental values for the resistors and voltage source, compute values for the node voltages and mesh currents. Place your results in the table (“analysis” column) of laboratory procedure step 2. Compute the percentage error for each experimental value in the “experimental vs. analysis” column of your data table. Consider the “analysis” values to be the reference. 2. Comment on the correspondence between experimental, simulated, and analysis results. Credits and Copyright Adapted from material developed by current and former ECE faculty, including Professor Joseph Kelemen. © 2008 Damon A. Miller and Frank L. Severance. All rights