% Author: Stephan Kregel, DG1HXJ
% Year: 2021
% 3-TD111, 3-TD112, 3-TD113
\begin{circuitikz}[european]
    \draw (-2,0) to [R,l=$R_\mathrm{1}$,o-*, i>^=$I$] (1,0);
    \draw (1,0) to [R,l_=$R_\mathrm{2}$,*-*] (1,-2);
    \draw (-2,-2) to [short,o-] (1,-2);
    \draw (1,0) -- (2,0) to [R,l=$R_\mathrm{3}$] (2,-2) -- (1,-2);
    \draw (-2,0) node[name=A, anchor=east]{$+$};
    \draw (-2,-2) node[name=B, anchor=east]{$-$};
    \draw [>=triangle 60, ->] (-2,-0.1) -- ++(0,-1.8);
    \draw (-2.25,-1) node[]{$U$};
\end{circuitikz}