Andrew Selle

Maybe adding a diode to prevent high voltages from outside from trying to reverse bias the emitter side would help? 

Yes agree that one opto isolator and circuit as is is the simplest option. I was thinking of the point of view that I don't really know how the other...

In the spirit of over-engineering to the extreme, I switched side of the output transisters (giving inverted output), ran them through schmidt trigger inverting buffers to cleanup incoming signal. Then...

Agree that it is overkill. greenout enable allows me to use a buffer that will drive the output to 0v faster. The problem with the optoisolator is it rounds the...

So I built up the circuit, and it works decently well. It uses 4 optocouplers (4n25s) , a cm4503bcn tri-state buffer to drive the 12v green line, a 74hct inverting...

I certainly understand, although I think in for most users, the presence of an enable pin really doesn't hurt them either as it could be safely ignored (unles someone is...

I'm happy to prepare an isolation schematic and submit it as PR w/o the logic chips.. probably next weekend, once I build and test it. -A On Mon, Jul 19,...

Sure, it makes sense. I was also planning to make a PCB design which I'd be happy to prepare as gerbers so people could order easily on oshpark or jlcpcb....

My more complicated circuit above has some errors in it. I can post it if anybody is interested (or I will put it in my fork). It mainly changed since...

Awesome. I saw your updated readme. The 4n25 were a bit iffy on CTR, as my last post said, but that's all I had. I noticed that sometimes on plugging...