I want to mention the concept of walkabout and then go for a meander with the ohmaps idea. The idea is to eventually look at if the ohmap extends from resistance (DC behaviour circuits) to impedence (AC circuits) in any useful way.

I introduced ohmaps in parts 1 and 2 and looked at some simpler examples.

We looked at parallel and series resistor networks (and combinations of those):

And I wrote this:

And not every resistor network can be shown as an ohmap – things outwith simple series/parallel nestings, like delta or Y networks.

It turns out I was a little hasty here. So how might ohmaps cope with more interesting networks?

I used JLCPCB to fabricate my cap-fun circuit (see part 1). It was under $20 including delivery, for 75 copies of this small PCB (4 x 4 cm).

I’ve been meaning to look into PCB fabrication forever, and it’s time, baby.

What would I make for my first small PCB? I settled on designing an educational demo board for capacitors. I call it cap-fun.

Capacitor demo boards are nothing new, but I’ve remixed things a little because the usual designs hide some nuances of capacitors that I think can be easily demonstrated.

More on Ohmaps: component failure battles, limitations, ambiguity…

Disclaimer: I am not an electrician. Nothing here is electrical advice/expertise. Insure your garments.

Occasionally there’s a lovely moment when I’m working on a problem and I realise I’m also looking at some other thing that seems completely unrelated. It’s like a metaphor made flesh.

These ‘ isomorphism moments’ can be powerful because the two seemingly unrelated things can give you insights into each other. Their commonality encourages you think about the essential thread running through them both.

This post details one of these moments I had recently.