plasmadrive Posted September 30, 2013 Share Posted September 30, 2013 I was having issues with my 2811 pixels icicles and spent all day Sat. troubleshooting them. Up and down in a bucket truck, over and over again. I wire tied all the icicles (40 meters worth) and the DC-DC converters (20 of them) to pieces of conduit under my eves. This made mounting and wiring much easier and spacing not an issue. (The 24v to 5v converters are used to inject power ever 2 meters of pixels) I am using two 6804s to control them. When I first fired them up, only 1 of the first 4 universes would work. (haven't gotten to the last 4). After a long time dealing with a bad 4 core T (open open leg) and a factory cross wired 4 core cable, I finally got all for working.. but.. three of them were having flashing issues. They were getting data but they would flash a bit. Very annoying. Almost like a flickering. So while I was attempting to clean up the cabling I noticed the flashing got worse. A lot worse. So I unbundled the cable coils and let them hang.. it got better.. still not stable, but better. My first thought was to make new shielded cables, but I thought I would try something else first. I wired two of the conduit pieces together and my intension was to ground them. Instead I connected them the common on the 24vdc supply. All of a sudden one of the converters went out and the other icicles stopped flashing. Turns out that internally, something was shortted to the case of the converter and it was causing the noise that was giving the data grief. I isolated that converter from the conduit (now an antenna) and all the others just in case, and tied all the conduits to the DC common. No more data issues. This noise issue took several hours and many trips up the bucket truck to deal with.. That combined with the bad cables from Ray Wu and I wasted my entire Sunday. Moral of the story.... Not sure there is one.. but if you use DC-DC converters for power injection, watch out for stray noise radiation. Still a great way to go, but damn that was frustrating. Link to comment Share on other sites More sharing options...
scubado Posted September 30, 2013 Share Posted September 30, 2013 I'm not very familiar with pixels, but why not use a couple good 5v power supplies? Link to comment Share on other sites More sharing options...
plasmadrive Posted September 30, 2013 Author Share Posted September 30, 2013 Simple, Much easier to use one 24vdc supply and run a single pair of #14 wires around the parimeter then it would be to run 120v power to 20 line side supplies, even with vampire plugs. (Ever try to start that many line side supplies at once from a single source?) I have a much lower impedence on the common (24v -) than if I were to rely on the strips themselves for all the common ties. I paid around $6 each for the DC-DC converters vs. waterproof power supplies, and I can tap where ever I want to from the 24vdc buss wires. I also use smaller converters for the 6804s. This way I also only have low voltage up there under the eves too.. (not that that really matters a whole bunch). I kinda thought is was cool to do it this way! I inject power in the middle of every 2 meter worth of strips (split 1m left and 1m right) so that my color temp stays constant thru out the entire 40 meters worth of WS2812B strips when I turn them on all white. I cut them into icicles so there are lots of 3 different length strips, each with it's own goes inna and goes outta cable. Every cable drops voltage as well. Each 2 meters worth draws a bit over 3 amps @ 5vdc. Had I now had the problem with that one converter, (and Ray's cables) it would have been a snap installing all this stuff. Link to comment Share on other sites More sharing options...
plasmadrive Posted October 1, 2013 Author Share Posted October 1, 2013 Update. The problem I found with the DC-DC converters is that the +5vdc was shorted to the metal case (heat sink). I found 4 of the 26 bad. other then that, these things seem to run great... Link to comment Share on other sites More sharing options...
SoCalJimH Posted October 1, 2013 Share Posted October 1, 2013 Glad for this topic! I was planning on using DC-DC converters. Will have to do some testing to avoid this issue. Thanks Plasmadrive! Link to comment Share on other sites More sharing options...
scubado Posted October 2, 2013 Share Posted October 2, 2013 Still sounds like stuff you don't need. Why not run 5v on the #14 wire and run taps off of that instead of these converters. Only need one supply, maybe two depending on how big a 5v supply you get. Link to comment Share on other sites More sharing options...
plasmadrive Posted October 9, 2013 Author Share Posted October 9, 2013 Still sounds like stuff you don't need. Why not run 5v on the #14 wire and run taps off of that instead of these converters. Only need one supply, maybe two depending on how big a 5v supply you get.All the reasons I said above plus I have two buildings separated by about 20' linear feet (40 wired feet) and about 130 linear feet worth of drops to power. That is about 40 meters worth of flex strips cut into little pieces with lots of connectors to deal with. There are still the same amount of injection points no matter what if I want the color temp to remain the same thru out. There are other things I could have done, sure, but this was clean, easy and changeble. Link to comment Share on other sites More sharing options...
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