CAD Program

Ed Stoller

I need to design a simple circuit and am looking for a free CAD program to make it nice. To keep it simple, I am looking for something just for electronics. Anybody have any suggestions.

len k

I just freehand it, can't stand the time it take to get fancy, time sink. Draftsmen used plastic templates with nice results.
But I've read in my magazines there's a light version of Spice that's free. It is an analysis and simulation software for Electronic Finite Elements Analysis and plots. But it may have the ability to do schematics, I don't know.

Searching under "free spice analysis software" brings up links. Look like some run for only 30 days. Can always reformat harddrive and reloaded operating system and software, maybe.
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Jim McIntyre

IF you just want to draw a schematic, and haven't use SPICE before, pen and paper might be the best way... BUT if you might be interested in circuit analysis, or have used SPICE before, I recommend Texas Instruments' TINA TI SPICE program. It's free, has a pretty intuitive user interface, at least for schematic entry, and it has a decent-sized library of components.

Another schematic entry program I've tinkered with is ExpressPCB's ExpressSCH. It's free, and they give it away hoping you'll use it and their other tools to lay out a PCB, which is their real business.


New member
A lot of electronic hobby types use Eagle.

The big drawback with it an most electronics cad programs is finding the parts you want to use in their libraries. The other is that the free version of Eagle limits the board size and can not be used commercially.

With eagle you first layout the schematic then the PCB layout program uses the schematic to prevent you from making mistakes. It does not create the board automatically from the schematic. Just forget about doing that. It takes a person on a very expensive program to do good automated layout.

Spice is a circuit simulator. The latest version of eagle have a tie in to spice. You have to use new, special, libraries that have both spice and eagle information for the parts.

A good place to find help is the ElectroTechOnline forum.