Thevenin and Things

So today in class we did a quick review over how to do source transformations, which I'm still a little weak on, but I can do them.  Onto Thevenin's Theorem.  Thevenin's Theorem is used to reduce circuits to a singe voltage and series resistor across a pair of terminals.  It's really just a renumeration of the superposition theorem, applied to reducing an entire circuit.  Nothing crazy here.  Norton's theorem should be on the way.
We closed out with another example of Thevenin's Theorem. Celebration on Thursday.  Hooray!

THE LAB - Thevenin's Theorem
We did a thing.  It involved reducing a circuit to its Thevenin equivalent circuit, and verifying our measurements with a the nodes connected to a potentiometer.
1. Thevenin equivalent circuit on the excellent EveryCircuit software


Here is Alex taking a picture of our calculations, and of course, our calculations as well.
2. Schematic used with actual resistance values in blue.


We set up for our lab by, and here's the key, measuring our resistors and voltages to avoid troubleshooting.  We laid out our resistors and their actual values on the circuit diagram.  See below.  Approximated values in green, and measured values in blue.

3. Measured and theoretical values for Thev Voltage & Resistance.
In the picture below on the left, you can see our theoretical values for Thevenin's voltage and resistance.  Our measured Thevenin's are at the top right.
5. Percent errorr
Alex sneakily erased our error, so I'll enumerate them here: error for Thevenin Voltage and Resistance were 6.7% and 1.5% respectively.

4. Load resistor, voltage, and power

Our load resistor varied from 0 to 9.1kOhms.
We finished by calculating Power vs Resistance of the potentiometer.  See the table in the middle of the picture for a table of potentiometer resistance and Voltage measured.  We predicted a roughly linear relationship between power and resistance from the equation
P = I^2 *R
6. Plot of Power vs Load
Our graph looked roughly linear: