03/08/2016

03-08-2016: Keep Going With Nodal Analysis

I. Introduction:

Last week, we were introduced to some nodal analysis problem, which had some more advantages over the Kirchoff's Law we did back then in 4B. Next. we were given a problem introducing the concept of super node

Today we were given the problem about super node. The concept was little hard to understand at first- if there was volt meter between the two essential nodes, we can treat at one super node and write one more restriction equation. After a few practices, we got better at it

Here is Professor Mason work for the super-node problem

V_1 is the voltage across the resistor on the left, V2 is across the bottom, and V3 is across the right hand side

We were asked to find the uncertainty in range measurement. We did that by choosing V2 and V1 to be maximum, then  set it to be minimum to find the output of the calculation. Fortunately, the change is not really significance (if we use 3 significant figures, then there is no change)

II. Lab:
We were asked to set up the same circuit using analog discovery to analyze. The 3V source would come from the yellow wire- wave function generator

Our recording of the three resistors

Setup and results to prove that our pre-lab calculation is correct

A close view of how we set up. Notice that the yellow wire stands for the 3V source

here is calculation for the percent error, which was about 4.36 percent and in the acceptable range

III. Mesh Analysis:
We were introduced to the mesh analysis, which was sort of the opposite way of solving problem compare to nodal analysis. We defined the loops inside to be mesh 1 and mesh 2, therefore, we should have two equations

We wrote down two equations of i1 and i2, then we used freemat to solve for i1 and i2

We used every circuit to check our result. It took us a while to figure out we had to ground the circuit to run it

At the very last moment, Professor Mason asked us the color code of the resistors we learned in 4B. The one we used are 4 band, with the 3rd band is the exponent, and the last one is percent error.

V. Conclusion:

Today we spent most of our time learning the supernode method and did some more practices for the nodal analysis. Then we did the lab to verify our number, which was correct. Then, we learned the concept of the mesh current, which was the opposite method to solve the circuit compared to the nodal analysis. Lastly, we reviewed the color code for the resistors we learned in 4B