# tikz - how can I differ from a capacitor positive and negative pins?

How can I use the positive and the negative pins from a capacitor as reference to connect another parts in tikz?

[pC, l=$C_{21}$, name=C21, -]


Is it possible also for the normal capacitors?

[C, l=$C_{20}$, name=C20, -]

• Welcome to TeX.SE! Can you please show us a short compilable tex code what you have tried so far? Can you also add an sketch/screenshot of that what you want to get? Then we do not have to guess what you are doing (and wnating) ... – Mensch Aug 14 at 20:37

If you want to draw only a symbol, use path command.

\documentclass[margin=3mm]{standalone}
\usepackage[oldvoltagedirection]{circuitikz}

\begin{document}

\begin{circuitikz}
\path (0,0) to [C, l=$C_{21}$, name=C21](1,0);
\end{circuitikz}
\end{document}


Now you can use the anchors of this symbol using it's name, like:

\documentclass[margin=3mm]{standalone}
\usepackage[oldvoltagedirection]{circuitikz}

\begin{document}

\begin{circuitikz}
\path (0,0) to [C, l=$C_{21}$, name=C21](1,0);
\draw (C21.east)--++(45:1);
\end{circuitikz}
\end{document}


And using with some TiKz:

\documentclass[margin=3mm]{standalone}
\usepackage[oldvoltagedirection]{circuitikz}

\begin{document}

\begin{circuitikz}
\path (0,0) to [C, l=$C_{21}$, name=C21](1,0);

\node at (-2,0) [draw, circle, minimum size=1cm, inner sep=0pt](circ2){1};
\node at (2,2) [draw, circle, minimum size=1cm, inner sep=0pt](circ1){2};

\draw (C21.east)--(circ1.-90);
\draw (C21.west)--(circ2.0);
\draw (C21.east)--++ (0:1) to [R,l_=$R_1$](3,0);

\end{circuitikz}
\end{document}


• Notice that instead of using a path of length 0, you can also use \node[Cshape](myC) at (whatever). You lose the labels (which are bound to the path, and given a path of 0 length, they work a bit out of luck), but it could be useful sometime. – Rmano Aug 20 at 9:31