Lab Day 8

EveryCircuit

This is the first example we did during class. We had to use EveryCircuit do create our circuit that was given in class.

This was the second example that we did in class.

This is the third example we did in class to find the Thevenin Equivalent.

Thevenin's Theorem Lab

In this lab, we experimentally investigated Thevenin's Theorem. We first analytically determined a Thevenin equivalent for the given circuit and then we experimentally determined the Thevenin resistance and the open-circuit voltage necessary to create the Thevenin equivalent circuit.

This picture is from out pre-lab. We determined the Thevenin equivalent circuit, the open-circuit voltage and the Thevenin resistance. The voltage was 0.4579V and the resistance was 7.2K ohms. 

The circuit is on the left side of the board, the measured resistance values are in the middle. We also measured the voltage across terminals a-b and is given by 0.459V. The percent error was 0.24% compared to the actual value from the pre-lab.

We then measured the Thevenin resistance seen at terminals a-b which was 7.14K ohms. The percent error was 0.83% compared to the actual value from the pre-lab. 

We then picked a random resistor for RL which was 7.9K ohms and we connected it between the terminals a-b in the circuit. Then we found the voltage across and the load resistance.  

We then built the Thevenin equivalent circuit we determined in the pre-lab. We found the voltage across the load resistor and compared it to the voltage from the previous step.

On the last step, we connected a potentiometer between terminals a-b. We then measured and recorded the load voltage as a function of potentiometer resistance. 

These four pictures shows our circuit and measured values.

We then calculated the power delivered to the Vload as a function of the load resistance. The first column from the left side are the values of the measured resistance values, then the voltage measured, then the load resistance values, and finally the load power values. To calculate the load power we used the formula P = V^2 / Rl

We then used excel to plot the graph load power vs. load resistance.