QElectroTech

Among FOSS software, this is likely one of the most advanced and professionally implemented solutions for drawing circuit diagrams and schematics for electrical systems. The focus here is on drawing wiring diagrams, contact diagrams, and standard-compliant representations of circuit diagrams and schematics of all kinds in the fields of electrical systems, process engineering, hydraulics, pneumatics, power engineering, electrical connection technology, and the like. It features simple “wiring” of components, automatic labeling of terminals and equipment, automatic cross-references in multi-page documentation, etc.Almost everything is just like in professional solutions.

The program allows for extensive customization options, including the creation of custom components and sheet headers. Details such as equipment labeling are also user-definable, so they can be tailored to meet the requirements of applicable standards, the project, or your own workflow.

There is one drawback that I consider significant. There is no proper unit system. Everything is defined in pixels (px) and percentages. For example, page layout is not based on common standards but is done using columns and rows, for which the width and height must be specified in px.

The documentation provides a conversion table for aspect ratios according to ISO 216, for which a rough approximation to the web standard (W3C) was apparently chosen based on 96 DPI, meaning that 1 mm corresponds to approximately 3.78 px.

However, regarding the drawing scale—based on everything I could find—the forum agreed on a conversion of 1 mm to 2 px for the display of symbols and objects. You must be careful when drawing, though, as not all included symbols adhere to this scale, since this consensus did not exist from the start. For drawing circuit diagrams and schematics alone, this may not matter too much, as the only concern is legibility on the page or paper. It does become a problem, however, when you have to draw views—such as of control panels, distribution cabinets, or similar—where not only must the drawn dimensions be correct, but the scale must also match the page format of the printed paper or exported PDFs (yes, many customers still require this, at least in my experience). But that is simply not possible at the moment—or, at best, only an approximation.

Currently, there is no way within the program to scale existing symbols and objects within a drawing. If you need an object, for example, twice as large for a detailed drawing or similar, you currently have to either redraw the element or scale it using a separate tool from the community and insert it into your library at the new size.

I don’t want to dwell on this too much, though, since this is, after all, a project run by volunteer developers—one that I’d like to encourage every user to support with their own efforts, as it’s still an extremely high-quality project. Once you know these things, you can handle them reasonably well after a bit of a learning curve, even if certain aspects are a bit complicated. And once you have some experience with it, you can produce results that are virtually on par with those of professional schematic design programs.

For a professional solution, I would only give it 2–3 stars. However, since this is such a high-quality FOSS project, backed by excellent support from a community of experts, it deserves an extra star.