Use the partway operator to trisect the sides of the triangle. Replace
\draw (\a:\T) to[short,*-*] (\a+120:\T);
by
\draw let \p1=(\a:\T), \p2=(\a+120:\T) in
(\p1) to[short,*-*] ($(\p1)!1/3!(\p2)$) -- (\p2);
This will draw a black dot at the origin of each line and at 1/3 of the line. This is sufficient for drawing all dots.
If you want to access the intersections by name for adding labels or further connections, add coordinate
instructions to the draw command.
\draw let \p1=(\a:\T), \p2=(\a+120:\T) in
(\p1) coordinate (\a a)
to[short,*-*] ($(\p1)!1/3!(\p2)$) coordinate (\a b)
-- (\p2);
E.g., the first line drawn is the horizontal line from 30 to 150 degrees. The vertices will be named (30a)
, (30b)
, (90b)
, and (150a)
. Now the two nodes can be labeled by
\draw (30b) node[below]{B};
\draw (90b) node[below]{A};

\documentclass[border=3pt]{standalone}
\usepackage{circuitikz}
\usetikzlibrary{positioning}
\begin{document}
\begin{tikzpicture}
\newcommand\T{1.5}
\foreach \a in {30,90,...,330}
\draw let \p1=(\a:\T), \p2=(\a+120:\T) in
(\p1) coordinate (\a a)
to[short,*-*] ($(\p1)!1/3!(\p2)$) coordinate (\a b)
-- (\p2);
\draw (90a) to[short,-o] +(0, 0.4)node[right] {C};
\draw (270a) to[short,-o] +(0,-0.4)node[left ] {D};
\draw (30b) node[below] {B};
\draw (90b) node[below] {A};
\end{tikzpicture}
\end{document}