myDAQ homework problem: DC Circuits > Thevenin Equivalent > Dependent and Independent Sources

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Problem Statement: Find the Thevenin equivalent circuit at the terminal pair A-B in symbolic form, i.e., derive equations for the Thevenin voltage V_TH and resistance R_TH in terms of the circuit element values. Evaluate the Thevenin equivalent circuit equations for R₁ = R₂ = 4.7 kW and m = -1.5, 0.5, 1.0, and 1.3.

Analysis:

• Show your complete solution process
• Use the node voltage method to determine the open-circuit voltage V_OC, use the mesh current method to find the short circuit current I_SC, and determine the Thevenin resistance as V_OC divided by I_SC
• See similar worked problems at Circuits Learned by Example Online (CLEO)

myDAQ Measurement:

• Measure the individual resistor values with the NI ELVISmx DMM ohmmeter
• Measure the independent source voltage (5V source)
• Download and run VCVS.vi (voltage-controlled voltage source) linked at the bottom of this page; the “gain” control corresponds to m
• Measure the open-circuit voltage with the NI ELVISmx DMM voltmeter
• Measure the short-circuit current with the NI ELVISmx DMM ammeter
• Follow along with the video clip below to confirm correct operation of your measurement setup

Comparison:

• Report percentage difference between calculated values and measured values
• Comment on your results for m = 1.0
• Include screenshot of ammeter for m = -1.5