When is power injection needed?

[Zano]

I want to add a prop that requires a 35 ft extension from the controller.  The rest of my props are close that I run a strand of 50 bullets per output, so I haven't ever needed or thought about power injection.  This prop requires at least 2 strands of 50 bullets together.  Can I connect both strands together for 100 bullets on a single output?  Or do I need to power inject between them?  How do you determine the max number of bullets before needing to power inject?  Is there some math on power output/consumption and distance?  I have  PixCon16 MkII with 12v output voltage with 4 max amps/channel

Another question about power injection.  If I do not power inject and attempt to connect 2, 3, 4, or more strands of bullets together, will it damage anything, or will they simply not turn on?  Will the entire strand not turn on, or will they start to fade the further away you get?  I want to make sure I don't do any damage.

[TheDucks]

Power injection is to maintain 12V +/- 10% at all places on the string. Failure leads to pool light quality or erratic operation.

Then there is the Amp draw to consider. 4A, stings have  per LED color and an All White value. If you avoid  lots of white, you can fudge a bit. Higher Amps = more voltage drop over distance (strings have smaller wires)

Strings also have a Node (3 channels each) limit. You can't just put additional strings end to end (even with power).  2 strings is pretty solid in all cases.

when you push the channel limits (DMX is 512), everything needs to be top notch.

Rather than fuss with PI, Why not put a Pixie 4 (Pixie 2 have built in power, but they are intended to be used with lower power CCR strings. not a prob if you use ALL LOR for the prop)

at the prop and avoid all the PI extra work?

 

 

[k6ccc]

I'm going to answer your last question first.  The only possible damage would be to blow a string fuse on the controller.  As for what will happen with longer and longer strings.  Generally with long strings the voltage gets low enough at the end that either the pixels flicker a bit or more commonly display a color shift - usually white becomes more pink.  How far you can go depends MASSIVELY on the pixels in use.  Some pixels are more sensitive to low voltage and some strings have smaller wire than others.  What all that means is that you need to try the actual pixels you will be using and look at them with all pixels in 100% white (worst case scenario).  Extensions are usually only a problem from a power standpoint if they are quite long or very small wire.  Most of my extensions are 18 AWG wire so that is not an issue.  However, particularly there are distance limits from controller to first pixel and pixel to pixel.  Those limits depend on the controller, the pixels, and the pixel technology in use.  Pixel to pixel distance is generally far more limited than controller to pixel.  So again, the best bet is to test what you will actually be doing. 

Be conservative with your testing.  For example, if you need to go 20 feet, don't test it at 20 feet.  Test at 25 or 30 feet.  The reason is that if you test at 20 feet and it works, what you may not know is that at 20 feet, 2 inches, it fails.  After things degrade in a year or two, maybe it only works to 19 feet.  If you know it will work to 30 feet when everything is new, your chances of it still working to 20 feet in five years are better.

 

[Zano]

Great info!  Thank you!

@TheDucksThe reason I wasn't considering adding a Pixie4 was that I have a PixCon16 (2 actually), and one of them still has some open outputs, so I was trying to utilize those before adding another controller.  Also, I wouldnt be able to purchase and add a controller in time for this year's display.  I could always use 2 outputs for this prop, but that would require excessive extension cords.  

I will try to do a little experimenting this weekend with some white light.

@k6ccc when you said extensions are only a problem from a power standpoint when they are quite long (and depends on specific parts and pieces) but, in general, how long are we talking about?  20ft, 50ft, 100ft?  I know at that point it would be ideal to add a controller, but just so I have a frame of reference.  Is there a general rule of thumb?

[TheDucks]

The digital signal deteriorates on longer cords (Square becomes rounded and lower level). Gen 2 Pixies improved the Max distance to first node.

 

One thing to do, is install Null pixels in the middle of longer runs, those regenerate the signal if you get erratic lights on the string. (they do nothing for power, so go with shorter strings and more cords for now)

[k6ccc]

1 hour ago, Zano said:

in general, how long are we talking about?  20ft, 50ft, 100ft?  I

For pixel to pixel, 50 or 100 feet will run out of data before it runs out of power - unless it's really small gauge wire.  For controller to first pixel, 50 most likely will work OK, but 100 would be pushing it.  As TheDucks said, you can add null pixels to increase the data distance.  As I said before, you really need to test it with the actual controller, pixels and wiring that you will be using.

 

[SeeFromSpace]

Greetings,

Why can’t you just run a heavier gage wire carrying the 12v. 18 gage is pretty puny. Buy some 12 or 14 gage low voltage landscape wire. Probably could get at Home Depot. That will greatly help the voltage drop situation. I run 12 gage wire from power supplies in my garage to my roof props. A great source for specialty wire is wireandcableyourway.com

[dibblejr]

1 hour ago, Zano said:

Great info!  Thank you!

@TheDucksThe reason I wasn't considering adding a Pixie4 was that I have a PixCon16 (2 actually), and one of them still has some open outputs, so I was trying to utilize those before adding another controller.  Also, I wouldnt be able to purchase and add a controller in time for this year's display.  I could always use 2 outputs for this prop, but that would require excessive extension cords.  

I will try to do a little experimenting this weekend with some white light.

@k6ccc when you said extensions are only a problem from a power standpoint when they are quite long (and depends on specific parts and pieces) but, in general, how long are we talking about?  20ft, 50ft, 100ft?  I know at that point it would be ideal to add a controller, but just so I have a frame of reference.  Is there a general rule of thumb?

If using extensions dont cheap out and try to use what some people I have helped has tried cat5/ cat6. stereo wire ect. IT DOES NOT WORK.

Purchase extensions from vendors that sell pixels. They will be around 18 ga which is still small but they are beter insulated and tested for pixels.

JR

[Zano]

thanks for all of the info!  I will do some testing this weekend and figure out the best option for my situation.  All of this helped a lot!