Name: Max Krauss

Email: mtkrauss@fortlewis.edu

Lab 2 - Review Superposition, Thevenin's Equivalent Circuit, and LTSpice

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The objective of this lab was to review topics taught in ENGR 201. Superposition and Thevenin's Equivalent Circuits are important circuit analysis techniques that are used often in the study of digital electronics. LTSpice is a very common circuit simulation tool that is very helpful with modeling ciruits. It is widely used in industry.

Materials: Pencil and Paper, LTSpice

Task 1: Review Superposition and Spice (50 points). Grading rubric: Spice code (10 points), hand calculation (10 points), simulation results (10 points), writing/formatting (20 points).

(Build the circuit in Spice code ONLY. Do not use symbols and schematics)

Figure 1: LTSpice Code for Task 1

Figure 2: Hand Calculations for Task 1

The following six screenshots verify my handwork above using LTSpice.

Figure 3: LTSpice Trace of I(R1)

Figure 4: LTSpice Trace of I(R2)

Figure 5: LTSpice Trace of I(R3)

Figure 6: LTSpice Trace of V(R1)

Figure 7: LTSpice Trace of V(R2)

Figure 8: LTSpice Trace of V(R3)

Task 2: Review Thevenin's Equivalent Circuit and RC time delay (50 points). Grading rubric: Spice code (10 points), hand calculation (10 points), simulation results (10 points), writing/formatting (20 points).

(Build the circuit in Spice code ONLY. Do not use symbols and schematics)

Figure 10: LTSpice Code for the orignial circuit in Task 2

Figure 9: Hand written work for task 2.

The following two screenshots verify the time constant calculated above in both the original circuit and the thevenin equivalent circuit.

Figure 10: Time constant from the simulation of the original ciruit.

Figure 11: LTSpice code for the Thevenin equivalent circuit.

Figure 11: Time constant from the simulation of the Thevenin equivalent circuit.

Conclusion: This lab was a good refresher to start the semester. It simply brushed the cobwebs off of prior knowledge from circuits I and helped.