Are you claiming the simulation results are wrong? That may be the case, but they are exactly what I expect. A change in current will cause a snaller change in voltage through a diode than through a resistor that is dropping a similar voltage. It’s all there in the I/V curves.

I will try to set this up in a real circuit and see what happens.

Bob

 

Whew, okay. Okay. After a lot of work and testing, I was able to determine that the LED strips freezing was caused by them having been damaged at some point during the wiring process. I've replaced the damaged strips and I'm happy to report the freezing is no longer an issue.

However, the glitches are still rampant. I took a series of videos and posted them to YouTube too show you the issue. Links are below.

When you see 4 colored lines, that means all 4 controllers are operating independently. When they are all displaying the same pattern, they are being controlled by controller 1 as per the circuit I drew up before.

I'm kind of running out of ideas for scary the issue could be. But right now I'm thinking:

1) Grounding loop somewhere
2) Improper grounding - something with how I've wired my circuit has encouraged the ground reference voltage to creep up to an unacceptable level (or something like that - I barely know what I'm talking about)
3) The data line wires are too long and need to be amplified.

Any thoughts?

 

Update: Uncommoning all the grounds on the DC side of all 3 PSUs and removing the repeater/buffer from the circuit gives me flashes at a rate of about 3 every 17mins or so.

I also noticed that when I did continuity tests across the DC V- terminals of the PSUs, I could hear a waveform coming from the multimeter. It still read no continuity on the screen, but I could definitely hear a quiet pulsating signal. I assume that's the data line of the LED controller. No idea if that's normal or not

 

I daisychained the LED strips' front-side ground wires. Problem solved.

Sigh... To think it was that simple the whole time...

My only remaining question is this: Should I daisychain the grounds together at the end of the strip too or is the front side fine?

 

If is was a problem with grounding, daisy chaining would make it worse, grounding should be a star, with all grounds coming to the same point. Daisy chaining does just what you don’t want: allows a voltage drop in one circuit effect the potential of the ground in another part.

That said, I doubt that differing ground potentials was ever the problem. Ground loops are important with AC and low level analog circuits. A ground potential differene in two AC powered devices introduces an AC signal into any signal going between the two devices, hence the audible hum you get with ground loops.

Wih DC and logic circuits, it is a different story. The high and low levels of digital signals are typically different by a couple if volts. So if the grounds are different by say, half a volt should not affect the interpretation of the logic level.

Bob