ECON 214-516 Equivalent Networks and Superposition

ECEN 214-516

Post-Lab 3

Equivalent Networks and Superposition

Procedure

Task 1: Verify Thévenin's equivalent

First we constructed the circuit in Figure 3.4 of the lab manual.

Figure 3.4: Task 1 Circuit

For the power source instead of the batteries we used the voltage source on the PMD to generate a constant 3V power source.
We measured the source first to make our calculations more accurate later.
Next, we used the voltmeter to measure the voltage across the load resistor of
Then, we tested the same voltage after trying a 470 resistor and then keeping the circuit open.

Task 2: Verify the superposition principle

First we constructed the circuit in Figure 3.5 of the lab manual.

Figure 3.5: Task 2 Circuit

For the power sources we used both wave generator power sources on the PMD, to generate the constant 3V and 4V.
We then measured the sources for better calculation accuracy.
Then, we measured the voltage accros the 1kΩ resistor with both power sources active.
Next, we tested the same voltage but withopen, them again with open.

Task 3: Check the superposition principle validity for a non-linear device

First, we constructed the circuit in Figure 3.6 of the lab manual.

Figure 3.6: Task 3 Circuit

For the rest of Task 3, we followed the same steps as Task 2. The key difference between Task 2 and 3 is that there is a diode between the 1kΩ and the 5.1kΩ resistors as shown in Figure 3.6.

Data Tables with Results

Task 1: Verify Thévenin's equivalent

Power Supply Voltage: 2.993 V

Table 1: Load Voltage and Load Resistance

2180 Ω	2000 Ω	0.764 V	1.597 V
2180 Ω	470 Ω	0.280 V	1.570 V
2180 Ω	Open Circuit	1.605 V	1.605 V

Task 2: Verify the superposition principle

Power Supply -: 2.992 V
Power Supply -: 3.992 V

Table 2: Load Voltage Given Different Power Sources

Parameter	Measured	Calculated	% difference	SPICE	% difference (SPICE to measured)
	3.992 V	4 V	0.200	4 V	0
	2.992 V	3 V	0.267	3 V	0
	0.283 V	0.291 V	2.75	0.291 V	2.75
	-0.570 V	-0.556 V	-2.52	-0.556 V	-2.52
	-0.280 V	-0.265 V	-5.66	-0.265 V	-5.66

Task 3: Check the superposition principle validity for a non-linear device

Power Supply -: 2.992 V
Power Supply -: 3.992 V

Table 3: Load Voltage Given Different Power Sources (with diode)

Parameter	Measured	Calculated	SPICE	% Error
	3.992 V	4 V	4 V
	2.992 V	3 V	3 V
	0.897 V		0.15 V
	0.830 V		2.255x10^-9 V
	1.11 V		1.125x10^-9 V

Equations and Calculations

Task 1: Verify Thévenin's equivalent

Task 2: Verify the superposition principle

Task 3: Check the superposition principle validity for a non-linear device

Discussion:

Task 1: Verify Thévenin's equivalent

In, the pre-lab for task 1 we found that the theoretical was approximately 1.61 V. This was then proved while performing task 1 in the lab. For each circuit was extremely close to 1.61 V. There is error with our measurements, due to a variety of different factors. One factor is that everything has resistance, including wires, so there can be loss in electricity to different things that should not really be part of the system in an ideal world.

Task 2 and 3: Verify the superposition principle

In task three, superposition will not work simply because the diode will stop electrons from flowing in different directions. The diode forces everything to go in the same direction and so no voltages can cancel others out.

Conclusion:

Over all, I found this lab interesting. I think that it could be useful to use the Thevenin equivalent technique in the real world in order to simplify a problem and make it easier to understand. I think this definitely has real world applications and I am glad we learned more about it in lab. I look forward to learning about more electrical engineering topics as the semester progresses.