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Circuit simulation software – Qucs

A Simple model in Qucs

A Simple model in Qucs

I spent a fairly large about of time trying to find some simulation software to meet the needs of this blog and the readers of this blog.  Some of the criteria I used in the search were:

Free or very low cost:  Most of us do not have hundreds or even thousands of dollars to spend on something we will probably use infrequently once we are past learning the principles.
Available for the three main operating systems:  I have readers that use Linux, Windows and MacOS, I want software that will work with all three.  I had previously been using a command line driven piece of software, but it only worked with Linux.

In addition to those two main requirements, I wanted software that will work with our simple “pencil and paper” models and then would later work for the full non-linear simulations.  A graphical user interface,GUI, would also be nice so I could easily draw the schematics.   LibreCAD can do it, but it is not designed for that, Kicad is really designed more for printed circuit board work.   It also would be nice if the software is available in several languages.   I know everyone reading my blog has to know English or at least runs it through an on-line translator, but I also know it is nice to have the software and manuals available in your native language.

I found all of those requirements plus a whole lot more in a program called Qucs, Quiet Universal Circuit Simulator.   The software is Open Source and published under the GPL license and is free to programmers and users.  I’ve created two videos about the software.  The first one describes somewhat what all it can do and some of why I am “ate up” with the Open Software concept.   The second video shows a very quick simple DC Simulation from blank screen through getting the actual answers.

I will be using this throughout this series on electronics design.   And now an explanation you are owed…:).  I have said, I do not want to start with using a simulation, but that we will start with the “pencil and paper models” so you will understand the function of each component.   I still believe that way and we will proceed that way.  I will use this software to draw the schematics for the pictures and I will double check my answers using a simulation of the pencil and paper models.   However, you really do need to do the work to understand the effect of each component.  Then once we are all feeling confident we will move on to the non-linear models and find out how far off we are and then next on to breadboarding and really see how far off we are.

If there are any of you out there that cannot see these videos because you have a low bandwidth connection or you live in a country that blocks youtube, please e-mail me and I will provide a summary of each video.   Also if there are people that would like to have closed caption available in their native language, I can produce a close caption file in English and you can translate it.   I am not going to go to the effort unless someone requests it.

This is a link to the Qucs website:


The first Video: A description of the software and how to download it.

The second video – A simple DC simulation from beginning to results.

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Circuit simulation software – Qucs” by Create-and-Make.com is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

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2 comments to Circuit simulation software – Qucs

  • Nice choice. I have wanted to play with one of these programs for some time. Price is right for learning. I will be following along to get a better feel for what is possible.


    • Gary

      You are welcome to follow along Fred, but my guess is your experience will have you far ahead of where I am going with this, especially in the short term. Just download it, play with it and check out some of the other documentation on the net.


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