zvacman Posted January 31, 2016 Share Posted January 31, 2016 Hi again from the second year rookie, actually first year RGB/Pixel rookie. I have a two fold question regarding my 12v setup. I have been putting together control boxes with the controller and 360 watt 12v power supplies for various props in locations on my property. First, how hard do you all push the power supplies to the maximum output? Second, how far can I go from a power supply to inject power into pixels? I have several power supplies that are using half or less of their rated outputs. Gurus please chime in, thanks. Z Link to comment Share on other sites More sharing options...
EmmienLightFan Posted January 31, 2016 Share Posted January 31, 2016 How far you go for power injection depends on wire. If you get some super thick stuff you could probably go for miles, but tiny tiny cheap speaker wire won't get you more than 5 meters. I never run a power supply above 80% of it's maximum rated output. Several people do go above that but because of this they are unable to use every pixel on full-white for very long, which I think is quite limiting. Always have some headroom with power supplies. They will last you so much longer! Link to comment Share on other sites More sharing options...
jerrymac Posted February 1, 2016 Share Posted February 1, 2016 80% of rated max is the safe bet. Power injection depends on the actual pixels , the size wire from the power supply, the actual output voltage and the distance from the power supply as well as 5V or 12 V. General statement would be 50 pixels for 5 volt and 100 pixels for 12 volt. Easy way to test is tp set all lights to white (100 % of R, G & B), with the same wires you are going to use and look for the white to start tuning to a reddish color, This will give you an fair idea that you have exceeded the volt drop limit for your pixels. Inject power before that point or at the end of that string/strip (power from both ends but NOT data from the end). You also must consider signal loss of data from the controller which depends a lot on the controller, 20 feet to 30 feet is about normal (some exceptions like the Falcon). Solve is null pixel (pixels). Link to comment Share on other sites More sharing options...
Vince4xmas Posted February 1, 2016 Share Posted February 1, 2016 Can I power inject in the middle of 100 pixels with success? Run data and ground to first pixel, then power inject (+12v and ground) between pixel 50 and 51. Link to comment Share on other sites More sharing options...
saxon Posted February 1, 2016 Share Posted February 1, 2016 23 minutes ago, Vince4xmas said: Can I power inject in the middle of 100 pixels with success? Run data and ground to first pixel, then power inject (+12v and ground) between pixel 50 and 51. absolutely. Although there is really no need to run the extra ground with your data (wont hurt). 12v Pixel nodes use less wattage and 100 should be no problem without injection in most cases. Strips at 12v usually can go about 60-65 which is the case with mine. If a person wanted to, they could run just data to the beginning of there strip and add the power to the end (or middle). It would be rare that someone would need to do this, but you could. On 1/31/2016 at 1:17 PM, zvacman said: Hi again from the second year rookie, actually first year RGB/Pixel rookie. I have a two fold question regarding my 12v setup. I have been putting together control boxes with the controller and 360 watt 12v power supplies for various props in locations on my property. First, how hard do you all push the power supplies to the maximum output? Second, how far can I go from a power supply to inject power into pixels? I have several power supplies that are using half or less of their rated outputs. Gurus please chime in, thanks. Z Like jerry said about wire size - you can a long way from your power supply if the wire is big enough. I use 16 gauge and is more than adequate. If you are thinking of adding power to a prop from 2 different power supplies, you can but the 2 12+ must not mix (the grounds can). Link to comment Share on other sites More sharing options...
EmmienLightFan Posted February 1, 2016 Share Posted February 1, 2016 55 minutes ago, Vince4xmas said: Can I power inject in the middle of 100 pixels with success? Run data and ground to first pixel, then power inject (+12v and ground) between pixel 50 and 51. Yes, this is good. If you are running both data and ground but no positive from the controller, this method makes sense. You probably don't need the extra ground, especially with 12v. Link to comment Share on other sites More sharing options...
k6ccc Posted February 1, 2016 Share Posted February 1, 2016 Call another vote for running power AND ground to your mid point power injection. Link to comment Share on other sites More sharing options...
zvacman Posted February 2, 2016 Author Share Posted February 2, 2016 I may be wrong, I am applying automotive 12v DC logic to this. The ground doesn't get "consumed" like the positive, so injecting ground shouldn't be nessesary. So long as you have a good ground it shouldn't matter if you are 2" or 200' away from the source it is just the vessel for excess positive to return. As with all electrical AC or DC wire size is always a factor, the smaller the wire the less current can pass through unobstructed. All if my supply wires are a minimum of 16AWG which should be more than sufficient. If my thinking is wrong please set me straight, I have 40' peaks on a 12/12 pitch roof I don't like going up there any more than I have to. It's not the fall that hurts, it's the sudden stop at the end! Z Link to comment Share on other sites More sharing options...
wbaker4 Posted February 2, 2016 Share Posted February 2, 2016 1 hour ago, zvacman said: The ground doesn't get "consumed" like the positive, so injecting ground shouldn't be nessesary. Ever look at your house wiring? Isn't neutral the same gauge as hot? So why shouldn't you "inject" the ground just as you would inject the positive? By injecting, you are essentially cutting resistance which leads to lower voltage drops. Link to comment Share on other sites More sharing options...
k6ccc Posted February 2, 2016 Share Posted February 2, 2016 Yes, your thinking is incorrect. In an automobile, normally the entire chassis is the ground wire. It does have resistance, but even though steel is a lousy conductor, there is a huge amount of it, so it is GENERALLY not noticed. A friend of mine had a car many years ago that had terrible alternator whine when he was transmitting on a trunk mounted 2-way radio. We spent many hours working on improving the +12 to make it clean. Could not get rid of the noise. Finally measured the voltage between the battery minus and the ground connection at the radio. Found almost a volt and a half. spent the next several hours working on the lousy GM ground design and the noise went away. In the case of wires, there is just as much voltage drop across a ground wire as there is a power wire. Link to comment Share on other sites More sharing options...
wmilkie Posted February 2, 2016 Share Posted February 2, 2016 In electronics, which rgb is, a good solid ground can sometimes be more important sometimes than the supply[for noise anyway] (the positive) plus, you need to apply ohms law; current in equals current out, the same current going thru the plus goes thru the ground; and current x resistance = voltage drop; etc, etc Link to comment Share on other sites More sharing options...
Grinch Posted February 2, 2016 Share Posted February 2, 2016 I am a firm believer in using the same size ground as the conductor. Eliminates many problems across a variety of electronic systems. I have seen improper ground size cause machine control problems on 12-24 volt systems,(Not Lights) and on systems all the way up to 18,000 volt (Again not lights). Basically it is just a good practice. Can you get a way with it at times?, sure. Link to comment Share on other sites More sharing options...
saxon Posted February 2, 2016 Share Posted February 2, 2016 3 hours ago, k6ccc said: Yes, your thinking is incorrect. In an automobile, normally the entire chassis is the ground wire. It does have resistance, but even though steel is a lousy conductor, there is a huge amount of it, so it is GENERALLY not noticed. A friend of mine had a car many years ago that had terrible alternator whine when he was transmitting on a trunk mounted 2-way radio. We spent many hours working on improving the +12 to make it clean. Could not get rid of the noise. Finally measured the voltage between the battery minus and the ground connection at the radio. Found almost a volt and a half. spent the next several hours working on the lousy GM ground design and the noise went away. In the case of wires, there is just as much voltage drop across a ground wire as there is a power wire. agree 100% few years ago had 234 pixels on one run here in my work room so I could test power requirement's. I injected just the 12+ and sure, it go brighter and added 20-30 extra pixels. then I added the ground to that same injection point and BAM twice as bright and got an extra 60 pixels. As someone on here once told me - if you only run the 12+, your only solving half the problem. Link to comment Share on other sites More sharing options...
wbaker4 Posted February 2, 2016 Share Posted February 2, 2016 Just don't use orange wire. (So sorry.... someone had to say it!). 1 Link to comment Share on other sites More sharing options...
Little_b Posted February 11, 2016 Share Posted February 11, 2016 Everyone has some great info on power injection. I just was wondering if there is a "best" design on where to inject it. Say you have a matrix, do you take a wire from each injection point to the power supply, OR can you just run 1 wire and daisy chain them together. For my design it's using 12v nodes with 16awg wire injecting about every 100 -120 nodes. All the power comes directly from the power supply and not through the controller board, due to overloading each output. (This also includeds not overloading the power supply). All power includes both the pos and neg at each injection point. Link to comment Share on other sites More sharing options...
k6ccc Posted February 11, 2016 Share Posted February 11, 2016 That kind of depends on what's practical. Each has their advantages and disadvantages. If you run a single pair of wires (plus and minus) to the power supply and then split it, you have to remember that there is more current so you will likely need to use larger wire.. However running a single 10 or 12 gauge set may be far easier to deal with than a bunch of 16 gauge wires. The other thing to keep in mind is fusing. If you run a fuse block near the pixels, then a single large wire set back to the power supply would be easier. On the other hand, if you have in-line type fuse holders, then individual wire sets to each power injection point may be easier. There's really no hard and fast rule that says what you have to do. Link to comment Share on other sites More sharing options...
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