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<blockquote style="position: relative; padding-left: 55px;"><section><a href="https://chaos.social/users/gsuberland/statuses/117023582342884289">Graham Sutherland / Polynomial (gsuberland@chaos.social)'s status on Monday, 03-Aug-2026 17:37:13 JST</a><a href="https://chaos.social/@gsuberland" title="gsuberland@chaos.social"><img src="https://gnusocial.jp/avatar/39473-48-20221126005119.webp" width="48" height="48" alt="Graham Sutherland / Polynomial" style="position: absolute; left: 0; top: 0;">Graham Sutherland / Polynomial</a><div><a href="https://chaos.social/@gsuberland/117023038653230331" rel="in-reply-to">in reply to</a></div></section><article><p>ran some simulations with a slew-rate limited push-pull driver and the hexagon light's vertices modelled as LTRAs. looks perfectly cromulent.</p></article><footer><a rel="bookmark" href="https://gnusocial.jp/conversation/6595893#notice-12984752">In conversation</a><time datetime="2026-08-03T17:37:13+09:00" title="Monday, 03-Aug-2026 17:37:13 JST">about a month ago</time> <span>from <span><a href="https://chaos.social/@gsuberland/117023582342884289" rel="external" title="Sent from chaos.social via ActivityPub">chaos.social</a></span></span><a href="https://chaos.social/@gsuberland/117023582342884289">permalink</a><h4>Attachments</h4><ol><li><label><a rel="external" href="https://gnusocial.jp/attachment/6310502">Circuit diagram. A square wave at 115200 hertz drives a pair of slew-rate limited half-bridge drivers, with the lower one inverted, emulating an RS422 driver with a slew-rate limiter connected to it. The outputs of those are OUT_H and OUT_L, like you'd expect to see for RS422. Each line feeds into a custom subcircuit for the hexlight, with an input and a termination output, plus ground since the LTRAs need those. The termination outputs are connected with the typical 680/120/680 resistor network for biasing and termination.</a></label><br><a href="https://assets.chaos.social/media_attachments/files/117/023/558/803/929/205/original/9a4014c1d3af602a.png" rel="external">https://assets.chaos.social/media_attachments/files/117/023/558/803/929/205/original/9a4014c1d3af602a.png</a></li><li><label><a rel="external" href="https://gnusocial.jp/attachment/6310503">input and output waveforms. they're basically identical, with the terminated output exhibiting some minor noise on top from reflections within the network.</a></label><br><a href="https://assets.chaos.social/media_attachments/files/117/023/560/085/373/413/original/0cf97d4f3cc62f5f.png" rel="external">https://assets.chaos.social/media_attachments/files/117/023/560/085/373/413/original/0cf97d4f3cc62f5f.png</a></li></ol></footer></blockquote>

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Graham Sutherland / Polynomial (gsuberland@chaos.social)'s status on Monday, 03-Aug-2026 17:37:13 JST Graham Sutherland / Polynomial
in reply to
ran some simulations with a slew-rate limited push-pull driver and the hexagon light's vertices modelled as LTRAs. looks perfectly cromulent.
In conversationabout a month ago from chaos.socialpermalink
Attachments
1. Circuit diagram. A square wave at 115200 hertz drives a pair of slew-rate limited half-bridge drivers, with the lower one inverted, emulating an RS422 driver with a slew-rate limiter connected to it. The outputs of those are OUT_H and OUT_L, like you'd expect to see for RS422. Each line feeds into a custom subcircuit for the hexlight, with an input and a termination output, plus ground since the LTRAs need those. The termination outputs are connected with the typical 680/120/680 resistor network for biasing and termination.
  https://assets.chaos.social/media_attachments/files/117/023/558/803/929/205/original/9a4014c1d3af602a.png
2. input and output waveforms. they're basically identical, with the terminated output exhibiting some minor noise on top from reflections within the network.
  https://assets.chaos.social/media_attachments/files/117/023/560/085/373/413/original/0cf97d4f3cc62f5f.png

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