\begin{circuit}0

% Origen
\at 0 0 \P1

% Cables
\- 2 r \P2

%Primer Resistor
\nl \spring1 {$R_1$} r
\- 1 r
\.1 

%Segundo resistor
\- 2 d
\nl \spring2 {$R_2$} d
\- 2 d \P3

%Cierre del circuito
\htopin P1
\connection3 {} c l

\atpin P3
\- 1 r 
\connection4 {} c r

%conectores
\atpin P1
\connection1 {$v_i$} c l

\atpin .1 
\- 1 r
\connection2 {$v_o$} c r



\end{circuit}