Dependent Sources

Dependent sources are important components. As an example, consider the circuit of Figure 9 which has a voltage controlled current source (VCCS) with a gain k=2 (amps per volt).

**Figure 9:** DC circuit with dependent source (k=2).
$\begin{figure} \begin{center} \epsfig{file=images/clab1img9.eps}\end{center}\end{figure}$

Load the file PSPICE file dc2.sch, Figure 10. This PSPICE schematic uses the VCCS part G. The independent voltage V_ab is provided to the VCCS using the BUBBLE part, whose attribute is a label. Bubbles with the same label always have the same voltage, and so estabilish an invisible connection. When using dependent sources, it is important to be careful and get the polarities right.

**Figure 10:** PSPICE schematic of DC circuit with dependent source.
$\begin{figure} \begin{center} \epsfig{file=images/clab1img10.eps}\end{center}\end{figure}$

Exercise. Calculate the nodal voltages and branch currents using theory, and compare against the PSPICE results.

[ENGN2211 Home]

ANU Engineering - ENGN2211