3/12/2015

Mesh analysis problem

 We began the day with a refresher on how to do mesh analysis.

New circuit analysis method with example problem

We then learned a new circuit analysis method that involved using KCL and KVL to solve the unknown values for the circuit. A new method of circuit analysis is needed because this circuit includes both current and voltage sources.

Results

The lab for the day required the use of mesh analysis in order to solve for i_1 and V_1. Before actually conducting the experiment we used mesh analysis to solve for i_1 and V_1. We calculated the V_1 to be 2.42V and i_1 to be 0.26mA. After building the circuit, we measured V_1 to be 2.45V and i_1 to be 0.26mA with a multimeter. We also calculated the percent error for V_1 to be 1.24% and i_1 to be 0%.

Circuit build

Above is the circuit built in order to measure V_1 and i_1.

Summary:

Today, we learned a new circuit analysis method that we can apply to circuits that include both voltage and current sources. We solved a circuit by "deleting" the current source and making the circuit into two loops that we can apply KVL. The lab was determined to be successful because of the small percent error that arose from our calculated V_1 and measured V_1 value. However, this percent error may be due in part to resistors having a different resistance value than what was originally calculated. We also learned about transistors and how we can use circuit analysis with them implemented in a circuit.  Below is a the circuit symbol for a transistor (a) but this can replaced by (b) in order to perform circuit analysis.