3

I am not entirely satisfied with the relative size of Operational Amplifier and (american) resistor in this simple circuit:

\begin{tikzpicture}[scale=2]
\draw
(0,0) node[op amp] (opamp) {}
(opamp.+) node[ground] {}
(opamp.-) to [short, *-o] ++(-0.3,0) node[left] (a) {$i_i$}
(opamp.out) node[right] {$v_o$}
(opamp.out) --++(0,0.6) to[R] ++(-1,0) -| (opamp.-)
;
\end{tikzpicture}

OpAmp_1

I thought the easiest way is to scale the resistor down, by changing the line to:

(opamp.out) --++(0,0.6) to[R,scale=0.8] ++(-1,0) -| (opamp.-)

However, what I get is this:

OpAmp_2

No matter how I tried (curly braces around the to operation, using a node instead), I could not get the desired effect for the bipole (term which, btw, is not really used in English to define one-ports, at least so tells me Google).

I resorted to scaling the rest of the elements up, because for nodes the procedure is no issue.

\begin{tikzpicture}[scale=2]
\draw
(0,0) node[op amp,scale=1.4] (opamp) {}
(opamp.+) node[ground] {}
(opamp.-) to [short, *-o] ++(-0.3,0) node[left] (a) {$i_i$}
(opamp.out) node[right] {$v_o$}
(opamp.out) --++(0,1) --++(-0.35,0) to[R] ++(-1,0) -| (opamp.-)
;
\end{tikzpicture}

OpAmp_3

However, I would like to know whether there is a proper way to scale the 'non-nodes' in circutikz and what the correct syntax would then be.

Michele Ancis
  • 151
  • 2
    Maybe help and possibly duplicate: https://tex.stackexchange.com/a/32169/31034 –  Jul 12 '19 at 13:56

1 Answers1

1

The following properties are defined for op amp.

\ctikzset{tripoles/op amp/width/.initial=1.7}
\ctikzset{tripoles/op amp/port width/.initial=.7}
\ctikzset{tripoles/op amp/height/.initial=1.4}
\ctikzset{tripoles/op amp/input height/.initial=.5}
\ctikzset{tripoles/op amp/up pos/.initial=.45}
\ctikzset{tripoles/op amp/font/.initial= \fontsize{10}{0}\selectfont\boldmath}%absolut font size needed!

Checkout this file for more such options for other shapes.

Jitendra Kumar
  • 485