Max Power Lab

The purpose of this experiment is to confirm the Maximum Power Transfer Theorem in a series circuit as well as determine the Thevinin Resistance using the theorem.

Procedure:

We start by building the simple circuit connected in series.

To record 15 different values for the potentiometer, we incremented the pot and recorded V_0 for about every 600 Ω.

The second part of the experiment was building the circuit below.

Power supply 4.5 V= 4.61 V
Power supply 9.0 V = 9.07 V

Once operational, we used logger pro to record current and voltage data at V_0 when changing the pot.

Analysis:
Part 1:
For the first circuit, we obtain these set of values.

Measured V0 (V)	Measured Rx (Ω)	Calc. P0 (W)
0	13.5	0.0000E+00
0.16	330	7.7576E-05
0.34	691	1.6729E-04
1.36	2280	8.1123E-04
1.53	2780	8.4205E-04
1.7	3270	8.8379E-04
1.87	3800	9.2024E-04
2.04	4440	9.3730E-04
2.21	5120	9.5393E-04
2.38	5940	9.5360E-04
2.54	6850	9.4184E-04
2.87	9200	8.9532E-04

Graph of measured V_0 vs R_x.



 From the plot of Power Vs. R_x we see that the highest point is around 5500 Ω.



The theoretical R_x for max power is 5600  Ω.
Error = 1.79%

Part 2:
From logger pro, we were able to obtain voltage, current, and power.

From the graph of power however, we could not determine the maximum point of power because of the noise due to the current.

Conclusion:
Part 1 was a success for the most part verifying that the Maximum Power Transfer Theorem; however, we could not confirm it for Part 2 since it was a failure because we were unable to locate the point where max power occured. The problem was because of the fact that the recording device for logger pro was too accurate when measuring small currents, and it recorded unwanted data/noise where as the DMM was much better at recording data.