\documentclass[]{standalone}
\input{./tikzpreamble}

\begin{document}
\begin{circuitikz}[scale=2]
    \draw[color=black, thick]

    (1,1.5) node[draw=black, fill=white, regular polygon, regular polygon sides=4] {PTH08T250W}

    (1, 2.35) node[below] {V$_{SS}$}
    (0,3) node[left] {9.6V}
        to [short, o-] (1, 3)
        to [short, -*] (1, 2.35)

    (1, .65) node[above] {GND}
    (0,0) node[left]{GND} 
        to [short, o-] (1,0)
        to [short,-*] (1, .65)


    (1.85, 1.7) node[left] {R$_S$}
    (1.85, 2) 
        to [short, *-] (2.4, 2)
        to [short, *-] (2.4, 3)
        to [pR, l={R$_\text{pot}$}] (4.5, 3)
        to [short, -*] (4.5, 2)

    (2.4, 2) 
        to [R={R$_\text{parallel}$}] (4.5, 2)
        to [short] (4.5, 1.4)

    (1.85, 1.4) 
        to [short, *-] (2.4, 1.4)
        to [R, l_={R$_\text{series}$}] (4.5, 1.4)

    (1.85, 1) node[left] {V$_O$}
    (1.85, 1) 
        to [short, *-] (2.4, 1)
        to [short] (2.4, 0)
        to [short] (3, 0)

    (3,0) node[right,draw=black] {MONITOR\_1V8}
    ; 
\end{circuitikz}
\end{document}