5v or 12v pixels

[Scooch]

I am planning on building a pixel matrix for this year.  It will be 84"x46" with 2" bulb spacing.  That makes 966 bulbs.  Controlled across 12 channels using the LOR PIXcon16.  My question is this.  Would it be better to us 5v or 12v pixels?  I have done some reading but do not completely understand some of the terminology used.  What is meant by power injecting?  Also, given the number of bulbs used, what is the best power supply to use for this matrix?  Any help or guidance that can be given would be greatly appreciated.

[plasmadrive]

You have a long way to go.. but it is not that hard to get there.

1st off, all of the pixels you are going to use are 5v if they are WS2811 or WS2812B.  Some of the strings and now some strips have on board regulators that can take 12v.  Or.. some strips use 3 LEDs as a pixel. (not what you want for a matrix).

If you are using bullet style the same thing applies.  They are actually 5v pixels but if you get the 12v kind, they have on board regulators that will take the 12v and regulate to 5v in each pixel. 

What all this means is that you will burn more power in heat with 12v pixels than 5v pixels.  If you have the power to spare you could just go 12v but since your longest distance it only 7', you could just use 5v pixels and call it a day.

Now, power injection.  What the means is that you feed power to the strips somewhere along the line that is not at the input side along with the data signal.  Again, you are only going 7' so the easiest for you would be to connect 5v at each end of each strip.  You might even get away with only feeding one end but whites might be a bit yellow at the end of the string if on full power.   I would put the power supplies as close the matrix as possible, perhaps just behind it.  Use a good gauge of wire so you don't get a lot of voltage drop at higher currents.  There is a lot of info on the subject that others have already done.. keep reading..

Craig

[jerry72]

Actually most pixels sold now a days are 12 volt. They are just as efficient as the 5v.  With  the 12 volt, you can run 100 nodes with out power injection, with the 5 volt, it is drastically less. 12 volt have been none ot hold up far better then the 5 volt. Price wise, the 5 volt are  a little cheaper. As far as power, I would use 2 350 watt 30 amp PSU's.

[uncledan]

1 hour ago, jerry72 said:

Actually most pixels sold now a days are 12 volt. They are just as efficient as the 5v.  With  the 12 volt, you can run 100 nodes with out power injection, with the 5 volt, it is drastically less. 12 volt have been none ot hold up far better then the 5 volt. Price wise, the 5 volt are  a little cheaper. As far as power, I would use 2 350 watt 30 amp PSU's.

Curious where you get your information...  I think you're the first person I've heard say 12v is as efficient as 5v in all the 5v vs 12v discussions I've come across.  Plasmadrive is spot on in his analysis of 5v vs 12v.  12v is much easier to deal with and power but less efficient.

[saxon]

2 hours ago, jerry72 said:

Actually most pixels sold now a days are 12 volt. They are just as efficient as the 5v.  With  the 12 volt, you can run 100 nodes with out power injection, with the 5 volt, it is drastically less. 12 volt have been none ot hold up far better then the 5 volt. Price wise, the 5 volt are  a little cheaper. As far as power, I would use 2 350 watt 30 amp PSU's.

Plasma is right, almost all pixels/LED are indeed 5 volt. Even when sold as 12 volt, the actual LEDs are closer to 5volt. As he explained, there is either a buck converter to deliver 5 volts to the LEDS or 3 LEDs(per pixel) are in series, splitting the voltage. So the only real difference in the 12v vs 5v strings and strips (other than efficiency) is the power than can be applied to them - you may apply 12volts to the strip, but the LEDs are most likely 5volt.

 

Scooch - IMO, I am a fan of 12 volt

[EmmienLightFan]

For a matrix, where each line is close and the power supply and controller are also nearby, I would do 5v. Connect + and - to the start and end of every line. Just one wire going up with "T" joins coming off it.

Each 5v pixel is 0.3w, so multiple the amount of pixels by 0.3, add 20% and find a power supply which can supply that or more.

[plasmadrive]

5 hours ago, jerry72 said:

Actually most pixels sold now a days are 12 volt. They are just as efficient as the 5v.  With  the 12 volt, you can run 100 nodes with out power injection, with the 5 volt, it is drastically less. 12 volt have been none ot hold up far better then the 5 volt. Price wise, the 5 volt are  a little cheaper. As far as power, I would use 2 350 watt 30 amp PSU's.

Sorry Jerry, but I have to disagree with you.  12v pixels are really 5v pixels and require a voltage regulator on board. This means there will be more power dissipation with 12v that does not exist with 5v. That fact lowers the efficiency. That is just a fact of physics.  
As for the 12v holding up far better, I don't have statistics on this, but I would not bet the farm on that.  The regulator adds another heat source and possible point of failure.  When the 12v pixels first came out there were failures all over the place. Since then it seems the manufacturers have done better, but I wouldn't bet they hold up better if both are installed and used correctly.  I personally think most failures now a days are caused by user error or water ingress.  Either voltage pixel is subject to those two problems.

Scooch, for your application, I would personally use 5v pixels for efficiency reasons and price.... unless you need a fairly long run from the power supply to the matrix.  But that is me. 

I use all 5v pixels except around my windows where I want 3 LEDs as a single pixel.  I also use DC-DC converters everywhere, but that is another subject we can use to get you even more confused!  ha ha.. 

Craig

[EmmienLightFan]

If you get +12v on the data line, your pixels and controller are gone. I have accidentally put 5v onto data and no problems at all.

[dougd]

Just do what I didnt do. Pick one and stay with it. For a while I had a large mixture of both. I have been slowly getting rid of the 12 volt pixels. 5 volt just makes more sense to me, especially in a matrix.

[EmmienLightFan]

53 minutes ago, dougd said:

Just do what I didnt do. Pick one and stay with it. For a while I had a large mixture of both. I have been slowly getting rid of the 12 volt pixels. 5 volt just makes more sense to me, especially in a matrix.

Mixing can be a good idea, but works best when all props are self contained (Each one or a small group of props have their own PSU/controller.)

Many people have mainly 12v, then use 5v for a matrix because it makes more sense.

Mixing voltages on the same controller gets tricky. I have two 12v pixel sticks/fire sticks this year on a controller where everything else is 5v. All I am doing is running data to the stick and linking the grounds on the PSUs. It works but if you are not careful things will go wrong.

[Scooch]

My longest runs will be 84 bulbs. Still good with 5v?  Thank you for your help. It is slowly coming together for me. Would it be possible for pictures of your setups?  Not so much how the bulbs are up or anything like that. I am more interested in the electrical from the controller to the matrix. 

[zman]

Well to be precise, LEDs are not 5V critters. 

If you look up the voltage required to drive Red/Green it is between 1,8-2.2V. Blue is 3.2-3.8V.

5V vs 12V "which is better" is not really the question. The application determines which voltage gets used. Matricies it makes sense to do 5V as power injection can be easier.

Long single runs, 12V may be the better way. 

[jerry72]

I am not about to debate anyone on here about what is better, last time i did that one of the regulars got their panties in a bunch and i got in trouble from their admin buddy. You all have at it.

[Mr. P]

Personally, I use all 12v as I like the ability to do longer runs without having to worry about power injection as much and voltage drop. If I was worried about efficiency and cost then I wouldn't have started in this hobby, we all knew this hobby was expensive when we started.

Your choice, your preference.

Edited September 4, 2016 by Mr. P

[uncledan]

2 hours ago, Scooch said:

My longest runs will be 84 bulbs. Still good with 5v?  Thank you for your help. It is slowly coming together for me. Would it be possible for pictures of your setups?  Not so much how the bulbs are up or anything like that. I am more interested in the electrical from the controller to the matrix. 

As a rule of thumb, 50 pixels with 5v and 100 with 12v before power injection is needed.  You can limit the intensity of the pixels to help a bit too.  Results will vary depending on pixels, wire, etc.  I have an 84x42 node matrix and I used 12v just because its easier.  5v may be more efficient but 12v is just easier for me. 

[k6ccc]

I have both in use.  My pixel tree and star are all 5V.  Each of the 12 strings on the tree is 50 WS2811 square node pixels and fed from the SanDevices E682 controller.  I don't need power injection.  The star consists of 360 pixels in four strings that each consist of a bunch of short pieces of 30 pixel per meter strips with jumpers between them totaling 90 pixels.  Each string is fed from one output from the E682.  Without getting too involved here, I am feeding power to either the far end of the strings, or near the far end as I found that there was voltage drop to the ends.  If you want to see what the star looks like inside, take a look at: http://newburghlights.org/pixel_tree.html#Star

The second E682 is driving 10 strings of GE Color Effects bulbs which are 5 volt devices.  The longest string of GECE bulbs is 25 bulbs, so no power injection is needed there.  Each E682 has a 5V 350 watt power supply from Ray Wu.

All of my year round pixels are 12 volt strips.  That consists of about 25 meters of 12V dumb strips that are controlled by three CMB16D controllers and currently a little over 20 meters of 12V WS2811 strips that are controlled by a pair of SanDevices E6804 controllers.  The longest run of the dumb strips is 6 meters and has power fed from both ends (largely because it was convenient - see http://newburghlights.org/Landscaping.html#TreeRing to see why).  The 30 foot run of WS2811 flat out HAD to have power injection.  With the strip at full white on all pixels, the voltage at the far end was about 8 volts.  I am feeding power to the far end.  All three CMB16Ds and one of the E6804s are fed from a 12V 350 watt Ray Wu power supply.  When I complete the landscaping project, There will be another about 35 meters of 12V WS2811 strips being driven from one of the existing E6804 controllers.  The longest strip will be about 18 meters long and will have power injection in several places. I will be adding a second 12V 350 watt power supply.

This year I will be adding a single string of GECE bulbs as a perimeter that will be driven by a third SanDevices E682 controller.  This one will become a danger zone next year as I will also be running some 12V WS2811 modules in coro candy canes.  I will have to be VERY careful about having both voltage in that one controller!

 

[plasmadrive]

38 minutes ago, uncledan said:

As a rule of thumb, 50 pixels with 5v and 100 with 12v before power injection is needed.  You can limit the intensity of the pixels to help a bit too.  Results will vary depending on pixels, wire, etc.  I have an 84x42 node matrix and I used 12v just because its easier.  5v may be more efficient but 12v is just easier for me. 

Those "rule of thumb" numbers are pretty accurate with a little slop allowed.  For 5v pixels he would need to feed from both ends if he wants the ability to have good whites at full power.  For a matrix that is not too complicated but it is more wiring than with 12v.  When he gets into the higher numbers of pixels the power loss does add up, but either will work. 

[plasmadrive]

2 hours ago, zman said:

Well to be precise, LEDs are not 5V critters. 

If you look up the voltage required to drive Red/Green it is between 1,8-2.2V. Blue is 3.2-3.8V.

5V vs 12V "which is better" is not really the question. The application determines which voltage gets used. Matricies it makes sense to do 5V as power injection can be easier.

Long single runs, 12V may be the better way. 

It's not so much the voltage required to drive the LEDs, it's the voltage required to drive the "pixel", which means it's electronics and how it is configured as a pixel by the manufacturer.  (5v or 12v)

But you are technically correct about the LED voltage... he will just never actually have to deal with those raw LED voltages luckily. 

[Orville]

In my experience using voltage regulators for projects on my model G scale trains, I have found that there is a significant difference in the heat generated from a 5VDC regulator and a 12VDC regulator.   I still have to sink the 5V regulator to a lead weight inside a locomotive to dissipate the heat, but the 12V regulator I have to add a metal fin assembly as well as sink it to the lead weight to keep it from thermally shutting down from it's own heat generation!  And those voltage regulators get very, very hot!   You can get a nice burn from one if they aren't heat sinked, and even if they are, they still get hot enough to give a good ouch if touched!

I've used assorted voltage regulators {5VDC, 9VDC, 12VDC} in other projects for Halloween and Christmas decor where I wanted to add just a small amount of L.E.D. lighting too, 5V regulators are what I always try to use and about 470 ohm resistors seem to work best for those applications running off a 9VDC or 9VAC adapter.  If using ~AC~ output adapters, I do have to add in a Full Wave Diode Bridge to maintain correct +/- polarity between the L.E.D.'s and the 5V regulator/resistor{s} to the L.E.D.'s so I don't burn the L.E.D.'s up.

 

So I have to also agree with PlasmaDrives assessment, having built my own projects as well as working in the electronics field for over 35+ years, he hit it spot on.

 

[mdnooyer]

Hello. I think i have a problem with my controllers and my rgb leds. I have 12v dmx rgb controllers (from aliexpress) and 12mm dmx rgb leds (5v). I made last Year the Singing faces with it. It workshop fine for 1 week. Then is saw leds with diverent colors. I think i blow some leds. Now i am searching for new leds. The problem i have is more on the small strings (eyes) what is the best i can do?

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