[MetaPost][1] has a library [MakeCirc][2] for making publication-style schematics.  Here is [the manual][3].

![enter image description here][4]

![enter image description here][5]


  [1]: http://en.wikipedia.org/wiki/MetaPost
  [2]: http://www.ctan.org/pkg/makecirc
  [3]: http://mirror.its.uidaho.edu/pub/tex-archive/graphics/metapost/contrib/macros/makecirc/MakeCirc-en.pdf
  [4]: https://i.sstatic.net/D6fL3.png
  [5]: https://i.sstatic.net/N62qg.png