s-Domain Capacitors and Inductors

Applying the Laplace transform to Ohm's law for inductors (18) we get in the s-domain

V(s) = sL I(s) - L i(0^-)

(22)

This has the circuit representation of Figure 23.

**Figure 23:** s-domain inductor.
$\begin{figure} \begin{center} \epsfig{file=images/sl.eps}\end{center}\end{figure}$

Similarly Ohm's law for capacitors (17) gives

$\begin{displaymath}V(s) = \frac{1}{sC} I(s) + \frac{v(0^-)}{s} \end{displaymath}$

(23)

with circuit representation Figure 24.

**Figure 24:** s-domain capacitor.
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We can use these to construct s-domain circuits.

ANU Engineering - ENGN2211