Faint glow from LED lights when off

[RoboticBrad]

I'm sorry if this has been answered before, I searched with no results. Some of my LED lights will not completely turn off when I'm not running a show. It appears as if it's about 5% or less of light that keeps glowing. Is this common and is there a solution? I bought all my lights from the same vendor and they are full wave rectified. It's not all of them, but a good amount remains very dim... frustrating! Is this just something I have to deal with on LED's?

[jaanth]

Do you have a snubber on the LEDs? A small resistance across the line, as described here http://forums.planetchristmas.com/index.php?/topic/36988-easiest-terminatorssnubbers-to-make/ Here is a video link that shows the problemhttp://www.youtube.com/watch?v=HO-KSZq9l64, that uses a night light as snubber.

 

Hope this helps.

 

.

[danbeveridge]

 are they all over or on specific channels?  i had same problem and was given the advice that i had a triac half-cooked.  i changed the channel with another with a lesser load and it stopped doing it.  i wish i had spare channels but don't.  someone can probably shed better light on this, but  i just thought it might be worth a try.  

[George Simmons]

I think Dan's on the right track.  If the OP was referring to how poorly the lights dim on slow fades, that would be pretty specific for needing a "snubber".  Basically, that's how you know you need one.

 

When a channel remains on dimly after you close up shop for the night, that's almost always a triac in the process of failing.  I've seen the same thing on a few channels over the years - ranging from dim glow to full on, and sometimes progressing from one to the other.  Fortunately I've reached the point of having spare channels laying around but it's still a PITA.

[-klb-]

Sometimes it is a symptom of the hot and neutral supply to the controller being swapped.

[Tony Shepherd]

I have the same problem and was thinking a snubber would sort it. The situation is that over the last week two or three sets of LEDs (all the same make) started to glow when off. The glow has progressively got brighter as time has passed but its only the first 20 or so of the string of 50. If I unplug them they go off. If I then plug them into another channel they come back on and if I plug a set which was ok into the channel with the lit LEDs then they are ok This tells me the controller is ok and the problem is the lights. I have added a set of 35 incandescent to the circuit to act as a snubber but this has no effect. I'm thinking its something with the particular make of lights. They were ok last year but they are progressively getting worse. Am I missing anything or does anyone have any other suggestions

Thanks

Tony

[-klb-]

Sounds like hot and neutral to your controller is swapped.

The controller only switches the hot side, which should be the narrow blade of your outlets/plugs. If they are swapped somewhere, power will always be present on the wide blade, and any leakage to ground will light up the LEDs. You can test with a multi meter, or there are fairly cheap ($10?) outlet testers that usually also have a GFCI test button. These usually identify swapped hot and neutral, as long as ground is not also messed up.

[Tony Shepherd]

Thanks I will check it out. it is possible as I'm in the uk and have to cut off the male end of a us extension lead to put on a plug to go into the 110 volt transformer.

Thanks

Tony

[Max-Paul]

Very interesting. Tony, your different than us yanks. I would think that the transformer would isolate the output from earth ground. Tell me this, is ether of the output leads tied to an earth ground lead? In the case of a center tapped secondary. Is the center tap grounded to earth?  If so, then there is a chance that the hot lead is not going to the fuses, but to what is the neutral of the controller. Effectively using the controller to switch the neutral side.

 

I have personally managed to see this twice over the past couple of years. See I use SPT wire to daisy chain the power to my controllers and I have to be very careful to NOT swap the hot and neutral leads.

But this problem of yours sounds like mine in the past. Half of the string lit, or maybe the whole string faintly.

[Tony Shepherd]

Max I'm happy the earthing is ok as both ends are three pin but it is possible the live and nuteral may be swapped. When I say transformers I have 5 industrial transformers one for each controller I will try to add a picture but still working out how to add pictures. I will also get a meter on the cables next weekend when it's light and the lights aren't on. I will let you know. Thanks. Tony

[Dennis Cherry]

I had some LED strings doing the faint glow and looked at my controller power, This controller had a non polarized plug, took the plug and rotated it 180 degrees and the lights went out.

 

When putting power input plus, either polarized or non polarized, you need to observe the Line side of the cord is connected to the Line input side of the controller.

 

Snubbers are used, but they are mainly used for fading problems.

[atver]

I too experienced this same condition until I switched the wires on the plug outlet. Once they were switched, the low glow in the LED's went away.

[JHolmes]

I had this same issue except my problem was that I set the minimum burn on the controllers to 10%.

If you go into the hardware utility, on the input/output page there is a part that says "Maximum/Minimum" on the left.

Make sure that is at 100% and 0%.

[dgrant]

I just ran into this a few nights ago on just one channel. The very small LED string on it, was staying on very dimly. Normally I leave the controllers all plugged in 24/7 but after seeing this for a couple of days and nothing I did, stopped it, I elected to pull the power for one night. The next morning, plugged it back in and the problem is gone. Now adding to the story, there had been ice/snow here and my thought was that this was the source of the problem. But I carefully looked over this channel's cables and found nothing and insured there was nothing shorting it out. Problem is gone for the moment.

[Max-Paul]

is this plug you pulled dgrant a 3 prong or two prong type plug? Are you positive that the plug did not get turned around 180 degrees if two prong?

[dgrant]

It was a two prong but when I plugged it back in, at the time, the lights were still faintly on. It was that night, after the show, that I disconnected power to the controllers completely for the night and the next day, when I plugged them back in, the problem was gone.

Its still very possible this was an ice/snow issue at that time, which is all gone for now. Looks like heavy rain chances ramp up the next couple of days so if the problem returns, then I'll know.

[Max-Paul]

dgrant,

When I had the problem the first year, it started out very faint. But after a rain the glow increased. This is cause the capacitive effect increases when the ground is moist. Ok, so you have a two prong plug. Meaning that it might be possible that you did not put the plug back in the way it was before you unplugged it. Meaning you might have swapped which prong was hot.

[dan martens]

I'm have the same type of issue I'm using 250 led on a mini tree and the first 10 led are staying on on a few channels and the rest of the channels are fine .10 channels are exactly the same type and count of led

I'm use 3 prong cords to the controler and three prong out to lights . Light are only two prong

Weird that the first 10 led are staying on and not the whole string.

[Tony Shepherd]

I have now tested the leads and they are wired correctly. If I swap the lights that come on faintly to another channel then they still come on and the ones I plug into the existing channel go off. This tells me that it is the lights rather than the channel. The tree has 8 led sets 3 are 60 strings of Philips lights whilst the others are 50 sets from Walgreens. All three of the Philips are playing up although there is one set of Walgreens which has just started. I have a very small transformer which I have tried and they are ok with this one but on any of the industrial transformers I have this problem. My conclusion is that it could be the output voltage from the industrial transformers or maybe the lights going bad.

[Dennis Cherry]

I have now tested the leads and they are wired correctly. If I swap the lights that come on faintly to another channel then they still come on and the ones I plug into the existing channel go off. This tells me that it is the lights rather than the channel. The tree has 8 led sets 3 are 60 strings of Philips lights whilst the others are 50 sets from Walgreens. All three of the Philips are playing up although there is one set of Walgreens which has just started. I have a very small transformer which I have tried and they are ok with this one but on any of the industrial transformers I have this problem. My conclusion is that it could be the output voltage from the industrial transformers or maybe the lights going bad.

 

Are you using an external common ground for all your lights? Not the power input side.