% Dynamic inverse-$\varGamma$-equivalent circuit for an induction machine
% Author: Erno Pentzin (2013)
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows.meta}
%%%<
\usepackage{verbatim}
%\usepackage[active,tightpage]{preview}
%\PreviewEnvironment{tikzpicture}
%\setlength\PreviewBorder{10pt}%
%%%>
\begin{comment}
:Title: Dynamic inverse-gamma-equivalent circuit for an induction machine
:Tags: Electrical engineering;circuitikz
:Author: Erno Pentzin
:Slug: induction-machine
\end{comment}
\usepackage[european]{circuitikz}
\begin{document}

\begin{circuitikz}
%  \draw[help lines] (0,0) grid (8,6);
%  \foreach \x in {0,...,32} \draw (\x,-1) node {\x};
%  \foreach \x in {0,...,15} \draw (-1,\x) node {\x};
  

  % uref
  \draw(0,3) to[V_<=\large{15V}, l^=\large{$U_{ref}$}] (0,5);
 
  % Switches
  \draw (4,1) node[spdt,xscale=-1, yscale=1, anchor=in] (z0) {};
  \draw (z0.in) node[anchor=south] {z0};
  \draw (z0.in) to[R=$8\cdot R_0$, a=8$k\Omega$] (6,1) -| (6,4);
  \draw (z0.out 1) node[anchor=south west] {\tiny{+15V}};
  \draw (z0.out 2) node[anchor=north west] {\tiny{0V}};
  
  \draw (4,3) node[spdt,xscale=-1, yscale=1, anchor=in] (z1) {};
  \draw (z1.in) node[anchor=south] {z1};
  \draw (z1.in) to[R=$4\cdot R_0$, a=4$k\Omega$] (6,3) -| (6,4);
  \draw (z1.out 1) node[anchor=south west] {\tiny{+15V}};
  \draw (z1.out 2) node[anchor=north west] {\tiny{0V}};


  %z2 ist auf 0V geschaltet, => ausgaenge vertauscht
  \draw (4,5) node[spdt,xscale=-1, yscale=-1, anchor=in] (z2) {};
  \draw (z2.in) node[anchor=south] {z2};
  \draw (z2.in) to[R=$2\cdot R_0$, a=2$k\Omega$] (6,5) -| (6,4);
  \draw (z2.out 2) node[anchor=south west] {\tiny{+15V}};
  \draw (z2.out 1) node[anchor=north west] {\tiny{0V}};

  
  \draw (4,7) node[spdt,xscale=-1, yscale=1, anchor=in] (z3) {};
  \draw (z3.in) node[anchor=south] {z3};
  \draw (z3.in) to[R=$R_0$, a=1$k\Omega$] (6,7) -| (6,4);
  \draw (z3.out 1) node[anchor=south west] {\tiny{+15V}};
  \draw (z3.out 2) node[anchor=north west] {\tiny{0V}};

  
  %alle schalterausgaenge nr. 1 verbinden
  \draw (z0.out 1) -| (1.5,2);
  \draw (z1.out 1) -| (1.5,2);
  \draw (z2.out 1) -| (1.5,2);
  \draw (z3.out 1) -| (1.5,2);
  % mit u_ref verbinden
  \draw (z3.out 1) -| (0,5);

  
  %alle schalterausgaenge nr. 2 verbinden
  \draw (z0.out 2) -| (2.5,2);
  \draw (z1.out 2) -| (2.5,2);
  \draw (z2.out 2) -| (2.5,2);
  \draw (z3.out 2) -| (2.5,2);
  % mit 0V verbinden
  \draw (z0.out 2) -| (0,3);
  % ground-ref anhaengen
  \draw (2.5,0.5) node[rground]{} to [short,-*] (2.5,0.68);

  % ausgang
  \draw(6,4) to[short,-o] (7,4){};
  \draw(7.5,3.5) node[]{\Large{$U_a$}};
  \draw[-{Triangle[scale=2.5, length=2, width=2]}](7,3.8) -- (7,3.2);
  \draw(7,3.8) to[short,->] (7,3.2);
  \draw (7,3) to[short,o-] (7,2.8) node[rground]{};
  
\end{circuitikz}

\end{document}