Runo's Power Design

One of my most important tools has been Mathcad - a mathematics software, in which I have developed a variety of tailor made and specialized worksheets intended for typical SMPS design.
Here is a small selection - some of them with examples of results:

  • Flyback, "discontinuous" as well as "continuous current mode" and "boundary conduction mode".

  • Booster for "power factor correction" with fixed frequency.

  • Booster for "power factor correction" with variable frequency - "boundary conduction mode" Boundary Conduction Mode.

  • Booster as a DC - DC converter.

  • Forward converter (buck with transformer).

  • Full bridge, half bridge and push-pull converter.

  • Half bridge and full bridge resonance converters of the LLC or the LCC type. Also see my guide to the LLC analysis worksheet here.

  • Inductor design, airgap, saturation etc.

  • Feedback loop with open loop and closed loop phase- and gain curves and step load response. A simple (buck) and a little more advanced (buck-boost) example.
    See also this article. Or this: Buck Converter Loop.

  • Spectrum of conducted emission and calculation of the necessary noise filter.

Still today, new worksheets are occasionally added to my assortment. By virtue of these tools I am often able to hit very close to the target in the first shot.
I find the "Try something - see if it gets better"-method very insufficient if used alone.


In recent years, unfortunately, Mathcad has undergone changes which make it less attractive as my preferred math software.
Therefore, at present, I am re-building my most important worksheets in an alternative math platform: JupyterLab.
JupyterLab is a popular, free, and open source software based on the Python programming language.
Here are some examples of what I achieved:

  • Flyback converter designer, fixed frequency, discontinuous or continuous current mode

  • Feedback loop buck-boost converter

  • Steady state LLC designer

  • Steady state LCC designer


Method of work


Phone +45 6476 1002