How to create a symbol for toroidal inductor with TikZ/CircuiTikZ?

Question

Sorry for my incorrect english.

I my opinion there is no symbol for toroidal inductor in the CircuiTikZ package. How can I create such a symbol in TikZ and combine it with circuit created with CircuiTikZ? Any other solution is welcome too. By the way: Maybe the authors (Massimo A. Redaelli, Stefan Lindner and Stefan Erhardt) of the CircuiTikZ package can include such a symbol in their package?

Here is my code (therewith I can create left and right side of my quest):

\documentclass{scrartcl}
\usepackage[european]{circuitikz}

\begin{document}
  \begin{circuitikz}
    \draw
      (0, 0) to [sV<=$u_g(t)$, i = $i_1(t)$] (0, 3) -- (3, 3) -- (4, 2)
             to [open] (7, 2) -- (8, 3) -- (11, 3)
             to [R = $R_2$, i = $i_2(t)$] (11, 0)
             to [C = $C$, v = $u_2(t)$] (8, 0) -- (7, 1)
             to [open] (4, 1) -- (3, 0)
             to [R = $R_1$, v = $u_1(t)$] (0, 0)
      (8, 3) to [open, v = $u_i(t)$, o-o] (8, 0);
  \end{circuitikz}
\end{document}

The result:

The missing middle part (toroidal inductor) looks:

Thank you for your help and effort in advance!

Answer 1

Yes, here is the code:

\documentclass{scrartcl}
\usepackage[european, cuteinductors]{circuitikz}
\begin{document}

  \begin{circuitikz}
    \draw
      (4.5, 2.5) node[transformer] (T) {}
      (0, 0)                     to [sV<=$u_g(t)$, i = $i_1(t)$] (0, 3) -- (3, 3) -- (T.A1)
      (T.B1) -- (6, 3) -- (9, 3) to [R = $R_2$, i = $i_2(t)$] (9, 0)
                                 to [C = $C$, v = $u_2(t)$]  (6, 0) -- (T.B2)
      (T.A2) -- (3, 0)           to [R = $R_1$, v = $u_1(t)$] (0, 0)
      (6, 3)                     to [open, v^=$u_i(t)$, o-o] (6, 0)
      (4, 1.425) node[left] {$N_1$}
      (5, 1.425) node[right] {$N_2$};
  \end{circuitikz}

\end{document}

And the result: