Lm13700 voltage control

[analogoutput]

There’s some discussion of homemade vactrols starting here:

My build progress

Finally got around to testing these things. Conclusion, they suck. [image] I tried out a bunch of different LDRs and LEDs. Here’s the best combo I could find, vs that same combo in a shrink tube DIY vactrol, vs a VTL5C3 from Thonk. The lens passes too much background light at low current, and loses too much light at high currents. I’ll be sticking to shrink tube.