write lab report for resistive circuits

EET 1010 LAB EXERCISE #9 Resistive Circuits

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THEVENIN’S THEOREM (Theory and Multisim)

Objectives: The objectives of this laboratory exercise are to verify the validity of a Thevenin equivalent

circuit, and to compare calculated current and voltage values with simulated values from Multisim

circuit analyses.

Procedure: A FLASH DRIVE IS NECESSARY – BRING ONE WITH YOU TO LAB!

1. Given the circuit in Figure 9-1 below, calculate the load current and voltage for a 0.1 k,

1.0 k, 2.0 k and 3.0 k resistive load placed across the A and B terminals.

2. Across terminals A and B, determine and draw the Thevenin Equivalent circuit. 3. Using the Thevenin Equivalent circuit, again calculate the load current and voltage for a

0.1 k, 1.0 k, 2.0 k and 3.0 k resistive load placed across the A and B terminals. 4. Using Multisim, construct the circuit in Figure 9-1, placing a load resistor across

terminals A and B (use a 1 k resistor, although this value is irrelevant). Save this circuit to a FLASH DRIVE.

5. Once the circuit is complete, perform the following analyses in Multisim:

Select the SIMULATE menu  ANALYSES  PARAMETER SWEEP 1. Analysis parameters TAB 2. Sweep parameter: 3. Device Type Resistor 4. Name RL 5. Points to sweep:

a. Sweep variation type: Linear

b. Start: 0 

c. Stop: 4 k d. Number of points: 11

e. Increment: 400  f. Analysis to sweep: DC Operating Point g. Group all traces on one plot “check this box” h. Display results in a table “select this”

6. Output TAB a. Select the codes for the load current and >Add> b. Select ‘Simulate’

7. A table will appear including all the increments of RL and the corresponding values of IL

10V

1kΩ 2.2kΩ

3.3kΩ

-

+

A

B

Figure 9-1

EET 1010 LAB EXERCISE #9 Resistive Circuits

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8. Select Tools  Export to EXCEL 9. EXCEL will open with table values

EXCEL 1. You will need to create/modify the RL column so that it has values only (for graphing) 2. You may also wish to put IL in mA (multiply by 1000) 3. Now go back to Multisim and perform another ‘Parameter Sweep’, repeat steps 1-9 for

output voltage, VL. (Be sure to remove IL from the selected variables list) 4. Add VL data to the first EXCEL sheet and save it to your flash drive. 5. Using the data above create 2 scatterplot (smooth lines and markers) graphs of VL vs.

RL and IL vs. RL for the original circuit. (RL is the independent variable and must be the horizontal axis.)

You will repeat this entire process on your own for the Thevenin Equivalent Circuit.

Data Analysis: 1. Create a Table of calculated IL and VL for the original circuit in Figure 9-1 and for the

Thevenin Equivalent Circuit. 2. Create a Table of simulated IL and VL for the original circuit and for the Thevenin

Equivalent Circuit . 3. Create graphs of IL vs. RL and VL vs. RL for the original circuit and for the Thevenin

Equivalent Circuit. Save all files created in the process of this lab – circuits, tables, and graphs Next week, this lab will be hard-wired in the lab. A submittal will be an accumulation of theoretical, simulated and measured results, but this will not be due until one week from the hard-wired completion.