Show HN: Simulator Visualizes Transistor Charge Carriers
28 Jul 2026
What happened
A developer posted a Show HN project featuring animations generated by a semiconductor simulator, visualizing how charge carriers move inside a transistor. The animations use a simple visual language: blue dots represent electrons, red dots represent holes, and white flashes mark recombination events — the moment an electron and hole meet and neutralize each other.
The project rolled out in three stages, each adding more physical detail:
- First set: Carrier velocity was shown as a combined diffusion-plus-drift current divided by total charge — but diffusion itself wasn't separately visualized.
- Second set: Carriers were shown undergoing both diffusion and drift explicitly, giving a more complete picture of the two transport mechanisms.
- Final set: Currents and voltages were added at each terminal, rounding out the simulation with circuit-level context.
What's missing
The report notes several open questions the Show HN post doesn't answer. There's no information on which simulator software or tool underlies the animations, no detail on the transistor type being modeled (MOSFET, BJT, or otherwise), and no word on the creator's background or intended audience. It's also unclear how the animations are delivered — as video, an interactive tool, or something downloadable.
More importantly, there's no validation data showing how closely the simulation matches real semiconductor physics, and no documentation of the underlying simulator. Both gaps limit how much technical scrutiny or reproducibility outside viewers can apply.
Why founders should care
This project is small in scope, but it points to a pattern worth watching. Visual, animated explanations of dense technical topics — like semiconductor physics — likely resonate with engineering students and self-taught learners who find textbook diagrams static and hard to parse. If similar visualization approaches could extend to other devices or STEM subjects, there's a plausible niche for founders building interactive or animated educational products in technical domains.
That said, the Show HN format itself is a signal: it suggests this is likely a hobby or early-stage exploration rather than a commercial product, since the creator appears to be seeking community feedback rather than customers. Founders eyeing this space should treat it as an early signal of interest rather than validated demand, and should factor in that technical accuracy and documentation — both currently missing here — would be prerequisites for any credible commercial education tool in this space.
The bottom line
A simple animation of electrons and holes moving through a transistor won't move markets on its own. But it's a reminder that developer communities continue to experiment with visual tools for explaining hard science, and that gap between technical depth and accessible visualization remains only partially filled.