ENGR338 Lab 2021 Spring
Lab 1 Superposition and Thevenin Review
Name: Keon Nez
Email: ktnez@fortlewis.edu
Superposition & Thevenin Review
Introduction
These theorems are extremely important in practice. Every time an engineer talks about input or output voltage/current it is applying these theorems implicitly. What an engineer seldom uses in practice, especially nowadays in the era of SPICE simulators, are all those methods for calculating all the electrical quantities in a circuit, like nodal or mesh analysis and the like. Although an engineer should know about them for theoretical reasons, spending too much time in becoming the master of nodal analysis resolution is not time well spent. Much better to learn how to apply Thevenin's and Superposition theorems (and a couple of other tricks) at a glance even in complicate circuits.

Method Calculations
Hand calculations of both Superposition and Thevenin circuit demonstration, to be tested in LTSpice. The SPICE simulations must be built using only spice code, not symbols/schematics.

Task 1:
Using the superposition theory to calculate all the voltages and currents in the following circuit. To verify all the values using LTSpice (Spice code only, Not using symbols/schematics).





Task 2:
Treating the 4nF CL as the load. I converted the circuit on the left hand side of CL into its Thevenin's equivalent circuit. Assigning a random PULSE function to the voltage source.






Results:
Recreate both circuits in LTSpice using only spice code. To test our theorectical calculations verses the LTSpice simulations results.

Task 1:



Task 2:
In order to define the parameters of the PULSE() function on my own. I had to show a nice time delay of my input/output and the output is fully charged to the full voltage during the periods.

The arguments in the PULSE() function are:   PULSE (LowVoltage   HighVoltage   Delay   RisingTime   FallingTime   OnTime   Period).



Discussion
The results of the LTSpice simulations were consistent with my hand calculations on paper. So I can conclude that the review was a complete success, to hone my skills back into circuits.