Week 3, Nodal Analysis

Week 3, Nodal Analysis

Summary: Use nodal analysis to find the voltage of a circuit. Construct the circuit, measure voltage and currents, and compare the measured values with the theoretical values.

Schematic
         

Equations for nodal analysis. The theoretical values for V2 and V3 are at the bottom.

Other theoretical calculation for the circuit.

 The actual values of the resistors and DC sources.

Final setup. The positions of all components are the same as they are in the schematic.

Measured values. Except for I(Bat2), all other values are very close to their theoretical values. See notes for the big percent error of I2.

If V2=V3=9V, plug in the equations above one gets V(Bat1)=9.9V, V(Bat2)=10.98V. Using 9.9V and 11.0V, the measured results are very close to the calculated results.

Notes: The reasons for the big difference of I(Bat2) may include:

1. The actual values are slightly different from the desired values. The calculated value will be 2.06mA if one uses all the actual values. The percent of error will be within a reasonable range.
2. The 1.5mA is a very small number. Usually meters are not as accurate in small scale as in large scale.