Day 7 - EveryCircuit, Linear Circuit, and Superposition

Topics Discussed

On day 7 of the ENGR 44 course, we discussed the topics of superposition and source transformation. These new tools would allow us to efficiently analyze circuits that may at first glance seem complex. We did practice problems that allowed us to exercise these new techniques (Fig. 1).

Fig. 1

Additionally, we were granted an EveryCircuit access code and practice using the program to double check calculations for various voltages, currents, and resistances through different elements in a circuit. We constructed our own circuits and were able to gain useful values for all the elements within the circuit (Fig. 2).

Fig. 2

Superposition II Lab

In the superposition II lab, we sought to test whether our not removing voltage sources would yield the same results for current and voltage as we calculated using the superposition technique of analyzing a circuit. First, we drew a diagram of our circuit and found the corresponding voltages of the 6.8k ohm resistor as we continuously changed which power source we were applying. (Fig. 3)

Fig. 3

Upon making our calculations, we proceeded to construct the circuit using a breadboard, analog discovery, wires, and the corresponding resistors. We then measured the voltage of the 6.8k ohm resistor and recorded our data. We compared the results found in the lab with those we had predicted, and found each result to be within 7% error (Fig. 4).

Fig. 4

Summary

In this lab, we were able to verify the technique of superposition and its practical application when doing real circuit analysis. We found that when disregarding some voltage sources, we were able to easily calculate the voltage across certain resistors. If each source was taken into account individually, we could then combine our calculated values to yield the true total voltage across a certain resistor. Our percent error was within 7% in all cases, which allowed us to verify the newly taught concept of superposition.