DiyLightAnimation
Hardware => Lynx Smart String => Topic started by: kjam22 on October 27, 2012,
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I ordered 15 dumb strings from ray and now that I am trying to burn them in I am finding quite a few bad nodes. I am finding around 5 or 6 nodes per 100 that are bad. Are others seeing this or do I have a bad lot?
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I ordered some metal square SSstrings. These are the ones with 4 LEDs per square. A few were "wrong" immediately.
On one, 2 of the 4 would not display Green. Red and Blue were fine.
On another, 2 of the 4 wouldn't do Red, just Green and Blue.
If I "massaged" them with power applied, they would occasionally come on properly. Take off the pressure and it stopped working.
I will just cut them out. It will go from 20 squares to 19. When I get a final count of bad squares, I'll let Ray know. Perhaps he'll toss in a extra string on my next order.
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Out of the the different form factors I have bought the squares had greatest failure rate.
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I had a lot of bad/flaky nodes testing with my SSC V1 with the smart string nodes, then I did the V3 mod and had two more strands to test and either Ray's average jumped greatly on those last strands of 128 or that mod made things not nearly as picky.
Still had like 2 Nodes that were bad but that was due to wires soldered out past the waterproofing and the connection broke.
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He will replace the bad nodes but it's the shipping that will kill ya. If you let him know, then he will include them in your next order.
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He's actually been pretty good at times to just send you nodes to replace the bad ones.
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Does he not include spares with the orders any more? I've only ordered lights from him once, was the end of last year but he had included spares of the string nodes and the rectangles floating around the shipping package.
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I didn't get any spares and I asked for samples of the smart nodes that I did not recieve. The death toll is rising, I have one string that has 10 bad nodes on it. At this rate I will be out a whole string of lights after I replace all of the bad nodes.
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I'm noticing the same problem. All 8 of my dumb strings that I've tested so far have around 5 bad nodes. With most of them, the red is out, a couple have the blue out. They all went out within the first hour of having them running. I'm so glad I decided to burn them in before I put them out. I'm hoping they're just a few bad nodes and the others won't start having the same problem after running for a few days.
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I ordered 6 strands of 100 and have had a total of 19 bad nodes. About 3/100.
Lots of splicing to do still. :-X
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That's about half the rate of mine. I keep trying to convince myself that something doesn't add up. It just doesn't make sense that there's that high of a rate on the dumb strings, when all they are is an led and a few resistors, and there's barely any problems with the smart strings. Out of all 2500 of my smart strings, there's about 2 bad nodes.
I've double checked the voltage, ensuring it's 12v and tried plugged the strings directly into the power but that didn't work. It also seems weird that no one else is complaining besides us few. Is 3-6 bad nodes per 100 normal for the dumb strings?
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I am not complaining about mine but I have found variation in color of my dumb strips and some bad nodes in my dumb strings. The failure rate I saw on the nodes was around 6%
Then again my original smart strings have had massive failures after the first season. The newer batches are rock solid but the first batch was atrocious...
Frank
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So I burned in all of my nodes and the final failure rate was around 8 percent. Mostly red failures and they seemed to be concentrated around the beginning of the string. I told ray about the problem and he sent me another string of nodes to replace the bad ones.
The new nodes appear to be made differently and he indicated that they were of better quality the the original ones. I hope to get them burned in this weekend so I will report if the failure rate is better.
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Yup, same here, mostly red and towards the beginning. I noticed something over the weekend on what causes the red to "burn out". I just received another batch of 8 strings that I ordered and plugged them in for 2 hours directly to 12v. There wasn't a single bad node, so I thought great, these are perfect. After hooking them all up outside, throwing a dsc on them, I immediately had problems. Some of the reds flickered for a couple minutes and then went out. I assume this has something to do with the pwm - those bad reds don't like to be turned on and off a lot.
The moral of the story - make sure you leave your lights flashing when you burn them in. Leaving them on for a couple hours isn't enough.
I don't have time this year to take them down and splice out all the bad nodes, so I'm thinking of covering the bad ones up with black gorrilla tape so they're not visible.
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I am also seeing additional failures. The count continues to rise on a daily basis. Still haven't had the opportunity to check out the new strings, but looks like I am going to have a bunch of splicing to do this weekend
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I am also seeing additional failures. The count continues to rise on a daily basis. Still haven't had the opportunity to check out the new strings, but looks like I am going to have a bunch of splicing to do this weekend
Your count is still rising? That's not promising. You started out with 5-6 bad nodes per string. What are you up to now?
I'm wondering if it's related to the DSC since that's new this year. Red is the most delicate color (requiring the lowest voltage drop). Is it possible that the DSC is somehow creating an inductor-like surge that's making the voltage > 12v. I don't have a way to check this. Just doesn't make sense how I had some of my lights running for 5+ hours without a problem and then within minutes of connecting them to the DSC the reds started blowing.
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It is more likely that the current limiting resistor value used for the Red LED is low. If enough people complain to Ray, he will get the manufacturer to bump up the resistance a little.
If you are using an adjustable power supply rather than a non-adjustable ATX supply, you could dial it down to 11.5 volts. The SSC or DSC wouldn't care (they have their own voltage regulators).
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That was one of my initial thoughts too, but wouldn't it have burned out while having it plugged directly into the power supply for hours? The reds only seem to burn out after being plugged into the DSC then into the same power supply. I do have my power supplies set exactly to 12.00. I'll try turning them down to 11.5 and see if any more burn out.
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do you have a link to the ones you bought?
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I bought the ones listed in the wiki, 100 node count. I am seeing almost an 8 percent failure rate - mostly red. I am going to swap out the bad nodes this weekend and see if I continue to get failures.
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I have two kinds of Dumb RGB in the display.
I have flex strips that I got from China, not from Ray. They are cut up and mounted around 2 window frames. They are connected (this year, anyway) to a 16 channel DC controller. Zero failures on these.
Then I have four strings of RGB dumb pixels mounted on a 4 layer mega-star. These were from Ray (indirectly, though - bought from someone who bought from Ray). There are 200 pixels total, and other than one string not having the same "white" appearance when All On, there are no failures. This is also on a DC controllers (not DSC). This one is using a power supply that was originally sold as 24vdc but easily adjusted down to 12vdc. If it fails at some point due to not being at its design voltage, I'll power from a SS Hub and ATX power.
My failures have only been in the Metal Square style SStrings. I bought 280 (14 strings of 20) and have had to cut/splice 8 pixels.
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Mine are the same ones from the wiki too.
JonB256 - Do you happen to have a DSC and be willing to try potentially burning some nodes? I have no more dumb strings left that don't have bad nodes to try testing with a different 4 channel DC controller.
BTW, I turned the voltage down to 11.5, and it looks like I've still lost a another couple nodes. Can't tell for sure since I haven't had a chance to cover up all the bad ones yet, but it looks like there's a couple more out. So don't rely 100% on this observation.
Can someone with a scope check the output from a DSC plugged into a set of dumb strings and see if there's any spikes or other anomalies or is anyone using the DSC with dumb strings and not having any problems?
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I have a scope but no DSCs. Seems like that is about the only thing from DLA that I don't have.
Well, no SSRs or stuff that pre-dates the LE version 5.
If you have a DSC (kit or built) I'd be willing to test. Now that my show is pretty much in auto, I'll have a chance.
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Since all the DSC seems to be doing is switching on a mosfet, I really doubt that it's the DSC. When this is happening, are you switching the LED's on and off a lot? I wonder if there is an issue with the nods themselves?
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I'm actually not switching them on and off at all. I'm leaving them at around 60%-80% brightness white, but since it's pwm, they're flashing on and off thousands of times per second. Look at it from this perspective and you'll have to agree it's the dsc - plugged directly into a 12v power supply for hours without any problems, then plugged into a DSC using that same 12v power supply and some reds (and one or two blues) flicker then burn out within minutes. That really sounds like the DSC, or the DSC in conjunction with the strings. I do realize there's nothing special about the DSC that could cause this to happen or that makes it different than any other pwm controller, but it's hard to ignore what's happening and blame it on bad nodes. If JonB256 had this problem with a different controller, then I'd blame the design of the strings.
JonB256, pm me your address and I'll send you a dsc to test. Thanks in advance for your help.
BTW, I'm up to around 9 bulbs per string out now. I just checked the voltage coming out with a multimeter and I'm getting 10.68v with my power supplies set to 11.5v using a 2ft cat5e cord. One might think that it's too low of a voltage, but if I plug it back into a power supply directly, the bad nodes don't come back on. And too low of a voltage wouldn't burn out a resistor and an led. I'm utterly confused now.
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Any one get anything figured out with the dumb nodes? I spent hours on Friday cutting and soldering bad nodes just to have many of the spliced nodes fail. For some reason they seem to mostly burn out near the beginning of the string.
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Are you sure you have 12 volt dumb strings?
All of the LEDs are really below about 2.3v and use a resistor to control the current. 12 volt ones have segments that are usually in groups of 3 LEDs.
As far as the cycling burning out the LEDs, not a chance. Over-current and heat are the two things that will destroy an LED. If you are getting a voltage spike or static electricity, that could cause the over-current, but at the rate it sounds like you are having issues, I would almost be willing to bet that you have 5 or 6 volt nodes...
Try just connecting to a 5 volt supply and see if you get a good white...
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I bought the nodes that are linked through the wiki, the should be 12v. I am having failures ith two different power supplies as well. One is a pc power supply the other is from ray. The failure rate seems to be the same between the 2
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rm357 - I also bought the ones linked through the wiki. Please note that I had no problems with the strings plugged directly into the power supply. Problems only (immediately) happened when plugged into the DSC, plugged into a hub, plugged into the same power supply.
kjam22 - don't bother soldering. Get some black vinyl tubing from the plumbing or pond section at lowes/home depot. I don't remember the size I got, but get one that fits snug over the lights. Then, put a piece of gorilla tape on one end. You're making black cap that you can use to cover up the bad nodes. Use a heat gun or hair drier to heat that up and they slip easily over a bad node. It's the quickest easiest way I've found. I'm not going to bother fixing my strings until we find out the problem.
I send a dsc to JonB256 last week. He's going to do some testing with his scope to see if anything crazy is going on.
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I send a dsc to JonB256 last week. He's going to do some testing with his scope to see if anything crazy is going on.
and I got it but haven't started testing yet. I have some rectangular Dumb Strings and some Dumb Flex Strips plus some 12vdc halogen lights for comparison.
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Wow. I was going to switch over to just dsc for next year since they have the same effect as the ssc except for the individual control but with this kinda failure rate old fashioned incans seem to be my best bet.
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I have not seen any failures on my dumb strings so far, but I do not have many in the display at this time. I have tested more, but they are not in the display.
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Jnealand - are you powering them with a dsc or with some other device? I have a 10 channel dmx rgb contoller from ray I might try to see if I have less failures.
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Yes, are you using a dsc to control your dumb strings? I'm still waiting to hear from someone that is controlling dumb strings with a dsc that isn't having problems.
devoidelk - I wish I would have used all ssc's this year and just treated the pixel strings has a dumb string. Out of all the thousands of pixel nodes I have this year, I've only had problems with 2 nodes.
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Davron, I still haven't put a scope to it (I'm off on Friday), but reviewing your posts, I see that your 12vdc power supply is "adjustable" not an ATX computer power supply.
It is possible that there are voltage spikes from your power supply when it is switched on and off (even at the as yet undetermined PWM switching rate).
Could you put a resistor (say 200 ohms or 330 ohms) across the power supply output? That would put a fixed, minimum load on the supply and reduce any wild swings. Not knowing the quality of the power supply's circuitry, it may be oscillating. A load resistor would stabilize it.
At 12vdc,
a 300ohm resistor would pull about 40 milliamps. That would be 1/2 watt.
a 1000ohm resistor would pull about 12 milliamps and just over 1/10 of a watt.
Watt do you have on hand?? :)
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I am using a DSC to control my one string that is in actual use. The others were to go with my big star on top of my mega tree, but I had to many things intefering with my getting everything done before I had to give up and put my old star back up or I wouldn't even have a mega tree this year. The DSC is just plugging into a passive hub and seems to be fine. I have not noticed any bad nodes at all (something I cannot say about my smart strings). Maybe I am lucky, I am using a PC power supply on the passive hub.
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Davron, I still haven't put a scope to it (I'm off on Friday), but reviewing your posts, I see that your 12vdc power supply is "adjustable" not an ATX computer power supply.
It is possible that there are voltage spikes from your power supply when it is switched on and off (even at the as yet undetermined PWM switching rate).
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I'll see what I have available and try that. The first 4 strings that I burned in were connected to an ATX power supply and ran into the same problem. So I'm not sure that's the culprit.
I'm attaching the pics you requested here as I couldn't find a way to do it in the PM. The dsc's are wired the standard way as described in the wiki.
I am using a DSC to control my one string that is in actual use. The others were to go with my big star on top of my mega tree, but I had to many things intefering with my getting everything done before I had to give up and put my old star back up or I wouldn't even have a mega tree this year. The DSC is just plugging into a passive hub and seems to be fine. I have not noticed any bad nodes at all (something I cannot say about my smart strings). Maybe I am lucky, I am using a PC power supply on the passive hub.
Are you using the DSC from this past group buy and when did you purchase your dumb string? I'm using DSC kits from this group buy http://diylightanimation.com/index.php?topic=8931.0 and purchased my dumb strings from Ray Wu 3 months ago.
kjam22 - when did you purchase your lights and controllers and as kits or pcbs?
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I have 4 controllers from the coop and 4 that I built by buying pcbs from the store and parts from Mouser. My dumb strings are the ones in the wiki. I went back to my order to check and the link is identical. Just my gut, but I am suspicious of your power source. You seem to be the only one posting about node failures and if there were major issues with the nodes, I believe we would be seeing a slew of posts about bad nodes just like we saw with the original smart nodes.
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I have a few hundred dumb nodes controlled by MR 16's this year.
0 failures.
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I bought 12 of the 100 pixel dumb strings from Ray. I have about 4 to 5 failures on every string. It is always either the red or blue (or both) LED that is out, never the green. I am using DSC's with ATX computer power supply to control them. The strings are spread over 3 different hubs/power supplies. Due to time constraints I didn't do much testing of the strings prior to setting them up outside so I can't say if this if these failures were there initially or have occurred since running them. I don't think I'm seeing increasing failures since my show has been running, but I haven't done specific counts. My sense is they are just bad or marginal nodes -- perhaps a bad run from Ray. I'll be contacting Ray to get replacements nodes and will have a do a bunch of splicing at the end of the season.
-Mike
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I have a few hundred dumb nodes controlled by MR 16's this year.
0 failures.
Davron, when I get your DSC hooked up, I'll compare the output to an MR16. They use the same MOSFET output.
Mokeefe, my dumb pixels are like Ray's but not from Ray. I have a few pixels that want to flicker at full power but seem fine at lower power. No complete failures, though. They are on an MR16.
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I have 4 controllers from the coop and 4 that I built by buying pcbs from the store and parts from Mouser. My dumb strings are the ones in the wiki. I went back to my order to check and the link is identical. Just my gut, but I am suspicious of your power source. You seem to be the only one posting about node failures and if there were major issues with the nodes, I believe we would be seeing a slew of posts about bad nodes just like we saw with the original smart nodes.
It could be power supply related, but I've have the same problem with two different types of power supplies - 12vdc led 400 watt power supplies, and an ATX power supply. I'm not the only one posting about failures, read the thread from the beginning. I think I'm just the one with the biggest mouth. Sorry.
So far, you're the only one using a DSC with a dumb string that has reported success, at least on this thread. Everyone else is using DSCs with other lights or using MR16s to power their dumb strings. I guess the one thing that's different about your situation is that you're powering just one string, so that is a lot less of a current being switched on and off.
I have a few hundred dumb nodes controlled by MR 16's this year.
0 failures.
Definitely seems to be DSC & dumb string related. Not either one alone. Seems very odd that everyone using MR16 hasn't had a bad node, but myself, mokeefe, kjam22, mitch09, and frankr are reporting between 5-10% failure rates.
I bought 12 of the 100 pixel dumb strings from Ray. I have about 4 to 5 failures on every string. It is always either the red or blue (or both) LED that is out, never the green. I am using DSC's with ATX computer power supply to control them. The strings are spread over 3 different hubs/power supplies. Due to time constraints I didn't do much testing of the strings prior to setting them up outside so I can't say if this if these failures were there initially or have occurred since running them. I don't think I'm seeing increasing failures since my show has been running, but I haven't done specific counts. My sense is they are just bad or marginal nodes -- perhaps a bad run from Ray. I'll be contacting Ray to get replacements nodes and will have a do a bunch of splicing at the end of the season.
Mike, you may want to hold off splicing. kjam22 and myself had fixed some of our strings, just to have them burn out again.
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is it always the red?
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is it always the red?
In my case the nodes lose the red, blue, or both channels. I don't have any that are missing green.
-Mike
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Red seems to be the first to go within minutes of being on, leaving a blue-ish looking node, and this is by far the most common problem. After being on for hours, some of the blues will also burn out, leaving green or yellow nodes. I haven't had any greens burn out either. The bad nodes are concentrated near the beginning on the strings, but can occur anywhere.
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So, some bad news. JonB256 checked the output coming out of the dsc and it looks clean and unlikely to be causing nodes to burn out. I guess that rules out the dsc causing the problem.
As soon as I get a chance, I'm going to try to cut open one of my bad nodes to check the resistors on it and see if they're too small. If that's the cause, it doesn't make sense that the lights don't burn out when plugged directly into the power supply.
The other idea I was wonder was maybe it's the amount of lights we're using causing some spikes from the power supplies. I have 6x100 dumb strings on one 400 watt switching supply. That should be around 18A flashing on and off at the same exact time (a little differently than the smart nodes which control the pwm themselves so they're probably not all in sync).
Other than that, I'm running out ideas.
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The only way to check that would be to put a meter in line with the power supply and measure the inrush current and voltage on a large amount of strings.
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I had already checked with a meter and my power supply doesn't budge, at least as far as my meter can tell. But that doesn't mean there isn't a quick couple millisecond spike.
Still haven't had a chance to cut open a bad node. I had thrown all my bad ones out that I had already spliced out. The only bad nodes I have are outside being used right now. I'll probably have to wait until I take my display down check one of the bad nodes.
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You would almost need a scope or recording meter to measure because the time span would be so short.
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You would almost need a scope or recording meter to measure because the time span would be so short.
My O-Scope showed no sign of huge inrush currents. I know I didn't have exactly the same power supply as davron, but it is his DSC powering my dumb flexible strip. The waveform is as crisp and clean as I've seen on other DC devices using MOSFETs. Just over 400hz waveform with no odd spikes or harmonics.
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JonB256 I was talking more in the line of measuring all 6 of his strings at once with his transformer to see if there was anything abnormal. My guess is you would find exactly as you did when you scoped his DSC and the issue is the LED's on the strings themselves. I was more thinking out loud as to narrow one more thing off the list.
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I have a feeling if it's not the resistors in the nodes being too low, I'm going to end up buying an o-scope myself to track down the problem.
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I was finally able to cut apart one of the bad nodes, and unfortunately I don't think there's anything wrong with it. The resistors used are
Blue - 430 ohms (3.4V)
Green - 430 ohms (3.4V)
Red - 560 ohms (0.8V)
All connections look soldered properly, with no cold solder joints, and nothing looks visually wrong or burnt. The only things that look a little peculiar is the selection of the red resistor which limits the led voltage drop to 0.8V, a little low for red leds (typically 1.8-2.2V). So our guesses about the resistor value being too low is wrong. Using a 560 ohm resistor though would use .224 watts, so 1/3 watt resistors should be used. I can't tell what wattage rating the resistor are, and I'm not sure what happens if that's exceeded. Does it change the resistance or just melt the resistor? The resistor isn't melted, shows no signs of damage, and still reads 559 ohms.
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do the dumb nodes use an 8mm led?
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using those resistors in the leds, you can only run 66 nodes on a dsc
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Wow. I was hoping to at least get 75-100 on a dsc for some elements. I wonder if the pixel changed? Maybe the ssc design can be modded/resistor upgrade to get at least 100? The MR16 is starting to look better for my plans... At least it makes sense why there were that many failures.
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Using more nodes than 66 wouldn't cause the others to fry, it would just be trying to use more amps than available and cause them to be dim or the colors not to look right.
Chris, yes they use the same led bulbs as our smart strings. Not that I'm doubting your calculations, but I remember measuring the amps used and it was under 4A. I don't have the exact number on me. I wanna say it was around 3.6-3.8A.
I think I see how you came up with your calculations 20mA*3*66=3.96A. But wouldn't that hold true for our smart strings, so they must not be 20mA for each color. Do you happen to have the operating specs for them? I'm guessing they are different than 20mA which totally changes my calculations.
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the 8mm rgbled specs are for 20mA of current.
and the resistors mentioned before land the current to about 20mA per color.
here are a pic of about 100 of them that i ordered.
http://diylightanimation.com/index.php?topic=7982.0
and here's the link on Ray's site for them...
http://www.aliexpress.com/store/product/8mm-RGB-Led-Common-Anode-4pin/701799_456699587.html
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If that's the case, how are we running 128 of the same leds (different circuitry) in under 4A in our smart strings? I'm not challenging you. I'm just puzzled.
Also, if that's true, wouldn't we be under powering our strings and not burning them out, and wouldn't the people using MR16s have the same problem?
I'm missing something.
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The current is not the fixed variable, the voltage is.
Assuming:
12 volt power supply
~1.8 volt for the red LED
Current = (12v - 1.8v)/560 ohms
Or about 18mA
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ok, but even with 18mA it pushes 4A to about 74 nodes...
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So we must be under powering all of our nodes - smart and dumb. Yes/no?
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don't know what the smart string resistors are
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As stated, we don't know the values of the resistors used, but I would expect that we are not hitting the maximum rated current as that would tend to reduce the life of the LEDs. You want to get close for maximum brightness, but you also want a margin for safety...
The number one enemy of LEDs is internal heat buildup. The maximum rated current is determined by the manufacturer based on the heat dissipation of the part at some ambient temperature, which is probably around 70F. Too much current will generate too much heat and damage the light producing region.
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Ok, so trying to tie this back to our problem at hand... we're not hitting the maximum rated current per led in our dumb strings. With the resistors used, it should be using a max of 20mA per color at 12V. I'm saying max of 20mA, because the red resistor is on the high side, probably only supplying 18mA. Further, a 100ct string is drawing under 4A, so the current per led is definitely under 20mA on average per color.
Chris brought up that we should only be using 66 bulbs because that should be 4A. If we add another 34 bulbs, that wouldn't increase the current per led. That would either cause our wiring to heat up and melt, or possibly damage our dsc, or cause a voltage drop near the end of the string and affect the colors of those nodes. Either way, it wouldn't over power and destroy the led.
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I was finally able to cut apart one of the bad nodes, and unfortunately I don't think there's anything wrong with it. The resistors used are
Blue - 430 ohms (3.4V)
Green - 430 ohms (3.4V)
Red - 560 ohms (0.8V)
I took apart a bad ss node today to compare...
the smart string nodes resistor values are... (at least from the first batch last year)
Blue - 510 ohms
Green - 510 ohms
Red - 560 ohms
which leaves me scratching my head, b/c then that leaves 17.86mA + 17.25mA + 17.45mA for the three colors which don't add up to the 29mA that the node is supposed to be using...
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Yeah, something about that doesn't add up, but unless that has something to do with over powering the reds, that's probably a different thread. Sorry, just trying to keep us on track of figuring out what's wrong with the dumb strings.
510, 510, 560 is good to know though. That means the red should definitely be fine in the dumb nodes. 510 and 510 may explain why occasionally a blue or green might go bad. That is a pretty big difference.
I had a hunch that may explain what's wrong. Can you measure the size of the resistors as close as possible so that we can determine their power rating? I measured the ones in the dumb strings and they're about 2mm x 1mm. Which would indicate that they're 1/8 watt resistors being used at twice their rating. I haven't taken apart a ss node, but they look bigger to me, like 3mm x 1.5mm, or 1/4 watt resistors. I'm not sure how much their values would change with twice the current running through them, but it wouldn't take much to over power the reds.
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That wouldn't explain why those using MR16s are reporting no problems and us using the dsc are reporting problems, unless those using the MR16s are using a different batch of dumb strings and the parts were swapped to make them cheaper. That's just a guess.
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i don't have anything to measure millimeters but they are the same size as the ones on the plastic rectangles, metal squares, and flex strips...
also the flex strips use
470 & 510 ohm resistors (for comparison, even though they power 5050's instead)
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That's what I figured. If they're the same ones on my flex strips, then they're bigger than the ones used on the dumb strings, so that could possibly be the problem.
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The blue and green LEDs have different voltage drops than the red, that's why their resistors are smaller.
None of this explains why they are burning out though...
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he was talking about physical size, like they might be a different wattage resistor.
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And the power usage for the blue and green resistors would be .172 watts, running at only 38% over their rating, causing not too much of a change of their resistance, and thus not burning out many of the blues or greens.
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I ordered 3 smart strings and had the last one had four bad strings.
The one of the wires came off the nodes coming out of the box.
I hope the new style will be better. The square ones.
http://www.aliexpress.com/store/product/DC12V-input-WS2811-pixel-node-100pcs-a-string-injection-molding-type/701799_722405450.html
I have been thinking how the fix the round ones.
Rap tap around the the node leaving about 1/4 inch on the wire side.
Get some hard rubber sealant in a tube and inject it into the wire end around the wires.
I think if we can find the right sealant rubber that would work.
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Anyone resolve this?
My interpretation :o of the thread is that there seems to be an issue with DSC's causing failures but not with MR16's. Also, you should not connect more than 66 nodes to a DSC but that does NOT cause the failure of leds. Am I way off?
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with the led's and the resistors, i can't confirm nor deny my calculations... it doesn't add up to me, but i can't figure out why.
can someone measure the voltage output of the mr16, and the dsc while under load, as a change in voltage would cause a change in the mA received by the leds.
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Not sure what to ad to this. I can say the original DSC and strign is still working after a few months continous running and then off and on use after that testing the conductor on the bench.
The DSC works the same as a MR16 it is jsut compact and only three channels. the are ways to make light strings that do no like to be dimmed and will cause them to fail bit not sure how the strings you are using are made. I am using he ones in the wiki.
RJ
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From what I've found, the problem appears to be that 1/8 watt resistors were used instead of 1/4 watt. I've been working with Ray to get that changed.
Chris' calculations are correct. At 66 RGB lights, we're at about 4 amps. The fact that we can have 100 lights on a string and still be able to measure the current at less than 4 amps, indicates that there's a voltage drop along the line and bulbs at the beginning will get a full 12V and those at the end will get less. RJ mentioned that "The last led's on the string are dimmer than the rest." in the faq. However, I can't tell the difference. Those that can should stick with shorter strings. I'm sticking with 100. This also explains why its the reds mostly at the beginning of the strings that are burning out. They're the ones getting a full 12v and overloading the resistors.
Why the MR16s don't have a problem and the DSC do, I'm going to guess it has to do with the output from the two controllers. The DSC is probably outputting a full 12v under load, and the MR16 is probably putting out less, under powering the strings and therefore not burning out the reds.
RJ - we're using the strings from Ray listed in the wiki too. If you've had yours running that long, can you see if the resistors in your dumb strings look smaller or the same size as the ones in the smart strings? If I hold mine side by side, you can easily tell they're smaller without having to cut them open. I wonder if there were a couple versions of the strings made.
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Mine is an early version and it has the same size as the smart strings.
The quote about the last light being dimmer was in relation to the Smart Strings.
RJ
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Mine is an early version and it has the same size as the smart strings.
That would explain why some people like myself are having problems and others are not. Mine are clearly smaller. I don't have a micrometer, but using a ruler, I'd say mine are 2.0mm x 1.25mm resistors, typically 1/8 watt. Do the math and you'll see that the red resistor actually uses double that.
The quote about the last light being dimmer was in relation to the Smart Strings.
I know, but I would assume it's for the same reason - voltage drop as you move down the string. They're the same leds. 20mA x 3 (per color) x 66 nodes = 3.96A. If 128 smart strings nodes is running under 4A total, then we're not running at full power, not that we need to be cause those babies are already blinding. I was just using that to point out that nodes at the start of either type of string are receiving a higher voltage (closer to 12V) than those at the end (less than 12V).
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I had four node wires come out of the node.
I think it would be good for Ray to send a few extra nods with each string.
You should ask for a few extra nodes when ordering.
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I had four node wires come out of the node.
you're using the string in place of the tackle, right? >:D
seriously though, how much pressure are you putting on the nodes for the wires to come out?
in a movable setting like on a horse, i'd attach the nodes to para cord.
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They broke off as I was taking them out of the bag to test them.
There was only one string that did this.
The other strings were fine.
Further inspecting showed the silicone were the wires were connected was lacking.
The factory didn't fill in the space completely leaving the wires being held in place by only the
solder joint.
Inspecting the good nodes showed that the wires were held in place by the silicone.
The more of the wire was being embedded in the silicone the more it seemed the wire was secure.
I connect the nodes to the tack and put no pressure n the wires once connected to the tack. I leave some slack in the wire to make sure the wire doesn't put pressure on the node.
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Where did you buy them ? If you bought them from ray, he honors the the things that he sells. He works hard to get us the quality we need and expect
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Yeah, just email him and he'll send you replacement nodes. He keeps asking me how many nodes burnt out on mine so he can replace them, but I'm waiting until the issue of nodes burning out is fixed before I replace them.
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I let him know about the problem. Ray didn't do any thing about it.
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Ray gave me a credit on my newest order (2 weeks ago) based on how many of the square pixels failed.
I offered to mail him some bad ones for exam but he said that they had fixed the production problem. Time will tell on that one.
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Here's an update on the bad pixel problem...
Ray modified the dumb strings and I've tested a new string for 2 weeks, constantly on, and haven't had any nodes burn out. Looks like the problem is resolved. I was going to wait longer before posting my update, but I thought everyone would like to know since there's the new DSC coop going on.
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I meant to say bad node problem, oops.
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does the resistors (or pcb) look different than the ones you've had trouble with?
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There are capacitors on the back side in parallel with each led, which I was a little apprehensive about. I was worried that it would affect dimming, but it doesn't. I believe this same change was also made to the new version of the pixels. According to the design Ray sent me, they should be larger wattage resistors, but I couldn't really tell looking at them through the plastic. I know that the resistor value was also changed for the red, but I don't know the exact new value. I was waiting for one to burn out before dissecting it. I'll take a look tonight in better lighting and see if I can tell for sure if they're bigger in size or not. All I know for sure right now is that they ran non-stop for over 2 weeks, which is more run-time than all of December for me, and there weren't any problems.
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hey, if they work great, then we dont need the details :)
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So I'm a little puzzled. The resistors appear to be the same physical size. If the resistor value went up enough that the wattage might have gone down enough, or that might not have even been the problem. I'm curious now how much current was being drawn on the old reds. I'll have to hook it up to my mm and check.
I did notice that wiring is a darker color now. Remembering reading on a different thread that Ray increased the size of the wiring for new smart strings, I tried to compare the old wire on the dumb strings to the new ones. I *think* that it may be thicker wiring now. It so hard to tell without a micrometer once you start going above 20awg. I can't visibly see a difference, but the new ones feel thicker between my fingers. This shouldn't have an impact on bad nodes. I'm just pointing this out as another improvement.
Whatever the case, it appears that dumb strings were produced for a while that worked, then sometime around August-November 2012 there was some sort of change that fried mostly reds, and now they've been changed and are working again.