\documentclass[border=2pt]{standalone}

% Circuit - Drawing
\usepackage{circuitikz}

% Notation
\usepackage{siunitx}

% Define Color
\definecolor{bluegray}{rgb}{0.4, 0.6, 0.8}

% Define Lenghts
\def\dx{0.3}
\def\dy{0.4667}
\def\x{10.75}
\def\xx{12.0}
\def\y{9.0}
%
\def\dX{0.4}
\def\dY{0.779}
\def\X{7.25}
\def\XX{6.0}
\def\Y{9}

% Tikz Library
\usetikzlibrary{angles, quotes, shapes, decorations.markings, calc}

% Style
%% Arrow in the middle
\tikzset{arrow inside/.style = {postaction=decorate,decoration={markings,mark=at position .52 with \arrow{latex}}}}

\begin{document}
	
	\begin{circuitikz}[scale=0.5]
		% Grid
%		\draw[help lines] (-1,-1) grid (18,14);
%		
%		\foreach \i in {0,1,2,3,...,12}
%		{
%			\node at (-2,\i) {$\i$};
%			\node at (\i,-2) {$\i$};
%		}
		
		% Transformer
		\draw[draw=black, line width = 2pt, fill = bluegray, even odd rule, rounded corners]
			(6, -0.5) rectangle ++(6,12) (7.25, 1) rectangle ++(3.5,9);
		
		% Cables	
		%% Left	
		\draw[line width=1.5pt] (6,2) -- +(-2,0);
		\draw[line width=1.5pt] (6,9) -- +(-2,0);	
		%	
		\foreach \i in {0,2,4,6}
		{	
			\draw[line width=1.5pt] (\X,\Y-\i*\dY) ..controls (\X+\dX, \Y-\i*\dY) and (\X+\dX,\Y-\dY-\i*\dY).. (\X,\Y-\dY-\i*\dY);
			
			\draw[line width=1.5pt] (\XX,\Y-\i*\dY-\dY) ..controls (\XX-\dX, \Y-\i*\dY-\dY) and (\XX-\dX,\Y-\i*\dY-2*\dY).. 
								(\XX,\Y-\i*\dY-2*\dY);
								
			\draw[line width=1.5pt] (\XX,\Y-\i*\dY) -- (\X,\Y-\i*\dY);
			
			\draw[line width=1.5pt] (\XX,\Y-\i*\dY-2*\dY) -- (\X,\Y-\i*\dY-2*\dY);
			
			\draw[line width=1.5pt] (\X,\Y-\i*\dY-2*\dY) ..controls (\X+\dX, \Y-\i*\dY-2*\dY) and (\X+\dX,\Y-\dY-\i*\dY-2*\dY).. (\X,\Y-\dY-\i*\dY-2*\dY);

		} 				
		%% Right		
		\draw[line width=1.5pt] (12,2) -- +(2,0);
		\draw[line width=1.5pt] (12,9) -- +(2,0);	
		%
		\foreach \i in {0,2,4,6,8,10,12}
		{	
			\draw[line width=1.5pt] (\x,\y-\i*\dy) ..controls (\x-\dx, \y-\i*\dy) and (\x-\dx,\y-\dy-\i*\dy).. (\x,\y-\dy-\i*\dy);
			
			\draw[line width=1.5pt] (\xx,\y-\i*\dy-\dy) ..controls (\xx+\dx, \y-\i*\dy-\dy) and (\xx+\dx,\y-\i*\dy-2*\dy).. 
								(\xx,\y-\i*\dy-2*\dy);
								
			\draw[line width=1.5pt] (\xx,\y-\i*\dy) -- (\x,\y-\i*\dy);
			
			\draw[line width=1.5pt] (\x,\y-\i*\dy-2*\dy) ..controls (\x-\dx, \y-\i*\dy-2*\dy) and (\x-\dx,\y-\dy-\i*\dy-2*\dy).. (\x,\y-\dy-\i*\dy-2*\dy);
			
			\draw[line width=1.5pt] (\xx,\y-\i*\dy-2*\dy) -- (\x,\y-\i*\dy-2*\dy);

		} 	
		
		% Magnetic Flux
		\draw[line width=0.8, rounded corners] (6.6,0.3) rectangle (11.4, 10.8);
		\draw[arrow inside, line width=0.8] (7,10.8) -- (11,10.8);
		\draw[arrow inside, line width=0.8] (11,0.3) -- (7,0.3);
		
		% Current Intensities
		%% Left
		\draw[line width=1, orange, -latex] (4.2,9.3) -- (5.8,9.3) node[above, pos=0.5, black] {\small$I_1$};
		\draw[line width=1, orange, latex-] (4.2,1.7) -- (5.8,1.7) node[below, pos=0.5, black] {\small$I_1$};
		%% Right
		\draw[line width=1, orange, -latex] (12.2,9.3) -- (13.8,9.3) node[above, pos=0.5, black] {\small$I_2$};
		\draw[line width=1, orange, latex-] (12.2,1.7) -- (13.8,1.7) node[below, pos=0.5, black] {\small$I_2$};
		
		% Node
		\draw (7.5,10.8) -- (6.4,12.5) -- (6.2, 12.5) node[left, pos=0.9] {\small$\Phi_B$}; 
	\end{circuitikz}

\end{document}