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Life & fun · July 24, 2026

IM

I made some transistor animations

Hi HN, I made some animations of the most important kinds of transistors using my semiconductor simulation, details of which are on the page. I tried to make the visuals as realistic as possible while also aiming for clarity. If you want to go beyond the charge carriers and look at, for example, the electric field, you can do so in the simulation software. The desktop software also has less common devices like IBGTs and SCRs that have similar animations. The last thread about my software was posted here about a year ago: https://news.ycombinator.com/item?id=43942279

I made some transistor animations launched on July 24, 2026 with 212 votes, #151 of 24,623 launches that month and more than 99% of that year's launches.

Visit brandonli.net ↗Alternativestop 1% of July 2026

In plain words

Transistor animations visualize how different semiconductor devices work using realistic simulations. The tool shows charge carrier movement in common transistors like BJTs and MOSFETs, with options to view additional details like electric fields. A companion desktop application includes less common devices such as IGBTs and SCRs with similar animations. It is designed for students and engineers learning semiconductor physics and device operation.

written from the facts on this page · September 2026

From the sources

In the following animations, blue and red dots represent electrons and holes, respectively. White flashes indicate recombination events. In this first set of animations, the velocity of charge carriers is equal to the combined diffusion and drift currents divided by the total charge. Diffusion is not shown here. NPN BJT In the next set of animations, the carriers undergo diffusion and drift. This is the most accurate way of depicting charge carrier motion, but is also more visually confusing. The final set of animations shows the currents and voltages at each terminal. The animations on this page made by Brandon Li are licensed under CC BY 4.0from brandonli.net

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