When spice simulation isn't deep enough... Very educational to show how circuit elements work "under the hood"...for example the LC example doesn't use an L element and a C element as building blocks, but rather it is the two metal plates in close contact which form the bulk of the circuit's capacitance and it is the loop of metal itself which form the inductance.

I wonder how they simulate EM in only 2 dimensions.

I also wonder why the simulator only allows to show E and D fields, and not H and B.

Fun. I am reminded of the long forgotten Zachtronics semiconductor game “KOHCTPYKTOP: Engineer of the People” [1]

[1] https://www.zachtronics.com/kohctpyktop-engineer-of-the-peop...

Did you know that archive supports old Flash games like this via the Ruffle Flash emulator?

https://web.archive.org/web/20160305205215/http://www.zachtr...

cefFlashbrowser can do it better

This is also available (with an included Flash emulator, so playable on modern machines) in Zach's free retrospective "Zach-like" [1]

[1] https://store.steampowered.com/app/1098840/ZACHLIKE/

ChipWizard is the updated version and it's in Last Call BBS (from Zachtronics).

Amazing work feels very similar to Paul Falstad page https://www.falstad.com/emstatic/index.html.

This really needs a WebGPU port. Multigrid on a GPU is moderately easy.

The similarity is likely not a coincidence!

> (c) Brandon Li, 2025. Ported to Javascript with the help of Paul Falstad.

Brandon here. I was very much inspired by Falstad's applets. I had him take a look at my simulation and he generously offered to make a JS port.

It looks awesome, and I want to express my special appreciation that you used red and blue instead of red and green.

Sebastian Lague has been making one of these and youtubing it, the videos are great here's the latest one https://www.youtube.com/watch?v=HGkuRp5HfH8

Note that these are at very different levels of detail. Lague's is at the digital logic level, while Brandon's is some level around atoms/electrons.

This looks exciting, but the images make it look like maybe it's two-dimensional?

So how accurate are the results?

The UI is rough but this is very impressive!

im super into stuff like this, takes me back to messing with circuit sims for hours

Very clean, educational and informative. Well done, from one Brandon to another!

Really sexy