circuit/block-diagram drawing

To make production quality circuit diagrams as well as block diagrams, I strongly recommend J. D. Aplevich's "circuit macros". It's well documented and actively maintained. See the examples produced by this package circuit macros examples

There is some learning curve, for example to be able to use the "dpic" graphing language to draw your own diagram. But the tool itself is very powerful.

For me there are two remaining issues:

1. no live update
2. svg output is lacking

I hacked up some Javascript to

(watch m4 file change)->[m4->dpic->latex->pdf]->svg->(show in html)

Here is the gist of it

// watch .m4 file

var chokidar = require('chokidar');
var resolve = require('path').resolve;
const touch = require('touch')
const {exec} = require('child_process')

chokidar.watch("*.m4").on('change', fn=>{
   let ff = resolve(fn)
   console.log(ff, "changed")
   exec("runtask.bat " + ff, {cwd:"../"}, (err,stdin,stdout)=>{
    console.log(err,stdin, stdout)
    touch("index.html") //svg updated
    })

})

Here is the runtask.bat for Windows

m4 pgf.m4 %1 | dpic -g > tmp.tex

C:\texlive\2017\bin\win32\pdflatex template.tex

tool\dist-64bits\pdf2svg template.pdf %~dpn1.svg
tool\dist-64bits\pdf2svg template.pdf %~dp1tmp.svg

That way, you can "draw" by writing m4/dpic code and see the result in the browser live; and svg is generated from pdf which looks a lot nicer.

Here is one: http://www.physicsbox.com/indexsolveelec2en.html

Here is where to look for others:

http://www.freebyte.com/electronics/

www.educypedia.be/electronics/easoftsim.htm

I am also using TikZ at the moment but you may wish to try http://blockdiag.com/