% transmission gate NORTH-SOUTH
\newsavebox{\tgatens}
\savebox{\tgatens}(6,9){
\begin{picture}(6,9)
\put(3,0){\line(0,1){2}}    % input
\put(0,2){\line(1,0){6}}
\put(0,2){\line(3,5){3}}
\put(3,7){\line(3,-5){3}}
\put(0,7){\line(1,0){6}}
\put(0,7){\line(3,-5){3}}
\put(3,2){\line(3,5){3}}
\put(3,7){\line(0,1){2}}
\put(0,4.5){\line(1,0){1.5}}
\put(5.4,4.5){\line(1,0){0.6}}
\put(5,4.5){\circle{0.8}}
\end{picture}
}