my project includes many LEDs (about 750). They are powered with 2 Meanwell switching power supplies, each being capable of delivering 130W. So powerwise there should be enough of it. (Power input every 5m)
The LEDs were running for 4 months without any problems, now lots of them are damaged. If I exchange a broken one, the strip lights probably for a day or two before the next LED is gone.
GND an DATA from the Arduino are connected to the strip, as well as both GND (resp V-) from the power supplies are connected to each other (and to the Arduino GND).
There is no pattern which LED might go dark next, so I assume it is a overvoltage issue or a heat issue (due to its randomness).
If the problem is heat, a possible fix should be feeding the 5V each meter (directly from the power supply) I think.
What would you recommend doing first to fix my problem? May bad quality LEDs be a problem?
PS: My DATA wire is rather long, but that should not cause any damage to the LEDs, right?
Monitor the power supply output. It could be unstable and poorly regulated.
Monitor the turn-on waveform of the power supply. Could be producing overshoots/undershoots.
5m is a long way to go for voltage. But if it worked in the past should be no problem. Of course it depends upon load.
If the problem is heat, a possible fix should be feeding the 5V each meter (directly from the power supply) I think.
No that will not affect an overheating problem.
Have you got a seriese resistor in each data line to each strip? Have you got a large capacitor on the power input to each strip at the strip? Have you got a 0.1uF ceramic capacitor across the power pins on each strip? This is because switching power supplies can be noisy.
Can you post a link to this power supply please?
My DATA wire is rather long, but that should not cause any damage to the LEDs, right?
Wrong. A long wire can pick up interference and also cause reflections on the line resulting at spikes on the data line in excess of the power supply and also negitave spikes below ground. This can damage the first LED in a strip.
And yes it could always be a problem of faulty LEDs especially the very cheap ones from China, some of them use LEDs from the reject bin.
A long Data wire would only affect the first LED, not all of them randomly. All necessary capacitors and the one resistor are in use.
I found something interesting: When connecting another Arduino directly to the beginning of the strip, the strip worked, so it must be an issue with the data wire. So my plan is no install this Arduino at the beginning of the strip and let it communicate with the main Arduino with simple serial commands.
But shortly after that, one LED (maybe the 15th) starts behaving strangely and fails eventually. After replacing it, the strip worked. But after a day, you guessed it, another one fails.
So my conclusion is that I saved money at the wrong place - let‘s see how better LEDs will perform. Does anybody have a good source apart those cheap ones from Amazon?
A long Data wire would only affect the first LED, not all of them randomly.
Not necessarily. Once you have high voltages spikes on them then this gets transferred onto the power supply line and distributed to other LEDs on the strip. This could cause any LED to fail.
In cases where a long data line is unavoidable, what would be the best course of action to avoid those spikes and/or interference? Twisted pair with one tied to ground? Series resistors at front and end of line?
Would this solution also apply for any other runs between separate segments of strip?