Hi everyone,

after watching the physical domain introduction webinar, a question popped up in my mind.

If you look at the table of domain analogies, Electrical Voltage equals Mechanical Speed while Current equals Force/Torque.

Is there a specific reason why it was chosen this way round? I always thought it to be much more intuitive to pair Voltage with Force/Torque and Current with (angular) speed.

Reason:

Current "flows", i.e. moves -> much like speed.

An inductor keeps current flowing, just like inertia keeps a mass moving.

A capacitor holds static charge. A static form of mechanical Energy storage is a spring, hence voltage would be paired with force and so on.

Now why has it been chosen the other way round? There must be a reason, I guess? Is it easier to solve some equations this way round?

Hi Wolfgang,

thanks for taking the time to answer the question. It was a good example to show the differences in the analogies.

In fact, it inspired me to draw up my proposed analogy.

I see how the spring-damper system looks more similar to the elctrical counterparts with PLECS's analogies. Mine on the other hand show a more intuitive usage of masses (inductors) and I prefer the analogies of speed->current / voltage->force.

But at least now I understand where PLEXIM is coming from and also why they made their decisions the way they are - personal preference.

Thanks!