% Author: Dr. Matthias Jung, DL9MJ
% Year: 2020
\begin{circuitikz}[american]
    \draw (0,0) node[transformer core](T){};
    
    \draw (T.A1) node [ocirc](I1){};
    \draw (T.A2) node [ocirc](I2){};
    \draw (T.B1) to [short] ++(1.0,0) coordinate(C1);
    \draw (T.B2) to [short] ++(1.0,0) coordinate(C2);
    
    \draw(T.A1) node[anchor=east]{a};
    \draw(T.A2) node[anchor=east]{b};
    \draw(T.north) node[anchor=south](D1){\small 1:4};
    \draw(D1.north) node[anchor=south]{\small ü};
    
    \draw(C1) to [european resistor, l={$R$}] (C2);
\end{circuitikz}