Free Schematic Software

Discussion in 'General Electronics Chat' started by gary1wang, Nov 16, 2012.

  1. gary1wang

    Thread Starter Member

    Sep 18, 2008

    I have to draw very big circuit schematic, more than 50 parts 500 pins, do you know any free circuit schematic software i can use. Thanks

  2. nerdegutta


    Dec 15, 2009

    My favorite is Eagle CAD, but with so many components, I think you have a board size issue. If you can fit all in a 100mm x 160mm, I'd go for Eagle.

    Which OS do you use? KiCAD is free, and I think with no limitations, for Linux.
  3. John P

    AAC Fanatic!

    Oct 14, 2008
    No! Don't go anywhere near Eagle. It has restrictions on board size and component count unless you pay them money.

    KiCAD works, though I haven't used it myself. It does both schematic capture and board layout.

    Personally I always recommend FreePCB for board layout, but that's all it does--not schematic capture, and you need a netlist to run it unless you want to work freeehand, which with 50 parts you'd be crazy to do (or you will become crazy while doing). I use an ancient version of OrCAD for capture, and I can't give copies away. But the two programs work together quite well.
  4. nerdegutta


    Dec 15, 2009
    Component count...?
  5. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    After using several schematic capture packages, all with PCB layout too, (one costing some 10K per seat) I'm quite happy with Kicad. I find it very easy to use with few quirks.

    I admit I may be aclimated to the quirks it does have, but it does all that I want it to do.
  6. nerdegutta


    Dec 15, 2009
    KiCAD has a nice, useful 3D feature in-built. That's handy.
  7. bertus


    Apr 5, 2008
    Last edited: Nov 17, 2012
  8. bpark1000

    New Member

    Jan 26, 2013
    Try Omniglyph download from Free version is limited in not allowing Gerber output in PCB software. I don't know what limits are in schematic side (I suspect none).

    This is a package that has capabilities way beyond "ordinary" schematic or PCB design (but doesn't have significant autorouting or circuit analysis capabilities). File format is in ASCII readable. Package accepts old Tengo and Autodesk format. Also generates/accepts Circad6, Circad5, Circad4 (WIN98), Circad3 (DOS) formats. I would recommend saving files in DOS format, as this is simpler and less prone to generate crazy fractional results that all 64 bit packages are prone to do.

    The SCH file is totally self-contained. All information extracted from component libraries is resident in the file. You can create your own SCH or PCB components within the app, and set up your own libraries. App also enables "wallpapering the workbench" with PCB photos to aid in reverse engineering boards you have no schematic for.
  9. sirch2

    Senior Member

    Jan 21, 2013
    TinyCad? AFAIK there are no restrictions and it seems reasonable to use, though I have never done as many as 500 pins, most I've done is about 40 components.
  10. GopherT

    AAC Fanatic!

    Nov 23, 2012
    I like DesignSpark supported by RS Electronics / Allied Electronics. Component Library is growing quickly, supports multilayer boards with unlimited components and area. Also has many output file formats including gerber and even old-school HP pen plotter formats (plotter files must be saved and sent to com port through DOS prompt "copy" command (likely another way but I haven't bothered looking).

    Auto-routing is not great but it has not been good on any I have bothered to learn. DS also allows directly building on the pcb layout view without drawing schematic first. Not the only one to do this but it drives me crazy when it is not supported.
  11. panic mode

    Senior Member

    Oct 10, 2011
    KiCad works for me. It is open source so no licensing BS or restrictions. making own parts is simple and easy. it has few quirks which are easy to work around. if you want to spend money on a commercial product, do some research and try things out, check what other users say etc before spending $$$.