3/21/2017 Classwork + "Mesh Analysis 2" Lab + "Time Varying Signals" Lab

3/21/2017

Class notes:
Today we finished up on Mesh analysis.  We were taught an easier way to reduce the amount of algebra in doing mesh analysis.
instead of doing

we could instead count separate them by each current. I.e. for counting i1 we could just do
12i1-6-2i2=0; which reduces the algebra by one line.
We learned about transistors, diodes, and doping.
Firstly we were taught on diode, where the arrow on the diagram shows the direction of the current.
Professor Mason then talked about doping, the process where a more electronegative/electropositive element is introduced to semiconductors like Silicon and germanium . If the process of doping uses a more electronegative element, then it will create an N type (negatively doped) semiconductor.
In order to create a diode, a p type and an n type is placed next to each other, which in turn create a "depletion zone" in the middle of the two. This zone has a balanced charge, which makes it hard for current to go through.
We also were taught on transistor (namely the BJT type), and were given some problem to solve regarding power, voltage, and current of a circuit with a BJT.




Lab:

- "Mesh Analysis 2" Lab

Setup:

Hand calculation on the theoretical value of the circuit

Different Values of the resistors:

Experimental value of the voltage drop in the 6.8k ohm resistor:

Experimental current going through the 10k ohm resistor

The voltage across the 10k ohm resistor

Setup of the breadboard :

*Note: We used 22k ohms resistor instead of the 20k resistor because there isn't any in the lab.

Theoretical value:
Based on the value that were printed out on the transistors, we got
I1= -.322 mA, and V1=5 V.

Experimental value:
We found that V1= 4.99V, and I1=.362 mA.

Comparing the theoretical and experimental value, we found that there is a .20% difference regarding V1, while I1 has 11.80% difference.

- "Time Varying Signals" Lab

Ramp up function in the wavegen

Ramp up function in the scope

Sin function in Wavegen

Sin function in scope

Summary:
- It is important to practice setting up the scope window to produce graph that is needed for the experiment result.
- Solving transistor by changing it to a current source and a voltage and a voltage source enables us to solve for a circuit using the things we have learned