Author Topic: Power limited to 5A fuses on board. How to use the max pixels per port?  (Read 133 times)

Offline MrTeaIOT

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On the F16v3 board manual https://docs.google.com/document/d/1S67ZVLgQRYsdqPhgfPkQucnFXvu1FmQAME9qnK5RixU/edit last page
stated that for 12v for 50 pixels draw 2.77A and 33.24 watts.  The board maximum pixel per port is 1024 pixels/nodes.  So if my calculation is correct each port cannot connect more than 100 pixels because draw is more that 5A (5.54) and the on board fuse will blown if use white colors with full intensity.  For 1024 pixels that will draw 56.7A max.  The board can handle max of 1024 pixels x 16 output ports.  How can you get to that limit if you only allow max of 5A per output port?  How does power injection comes to play?  How to configure so you can use the max pixels per port without blown the 5A fuses?

Offline jnealand

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Re: Power limited to 5A fuses on board. How to use the max pixels per port?
« Reply #1 on: February 13, 2018, 09:18:49 AM »
1024 has to do with data control and not direct power from the board.  The most 12v nodes I have ever effectively used off one board connection was 128.  General wisdom is that after 100 nodes you MUST use power injection.  Beware using anyone's power calculations but those that you personally measure using the nodes that you have bought.  Way too much variation can occur between vendors and even same vendor different year and / or model even with the same chip.  I use a lot of strings that are 120 nodes, but I keep my power down by limiting brightness to 30%.  YMMV
Jim Nealand
Kennesaw, GA
Falcon and Lynx, all 12v
Multisync with Pi and BBB
P10 and P5

Offline k6ccc

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Re: Power limited to 5A fuses on board. How to use the max pixels per port?
« Reply #2 on: February 13, 2018, 12:33:38 PM »
On the F16v3 board manual https://docs.google.com/document/d/1S67ZVLgQRYsdqPhgfPkQucnFXvu1FmQAME9qnK5RixU/edit last page
stated that for 12v for 50 pixels draw 2.77A and 33.24 watts.  The board maximum pixel per port is 1024 pixels/nodes.  So if my calculation is correct each port cannot connect more than 100 pixels because draw is more that 5A (5.54) and the on board fuse will blown if use white colors with full intensity.  For 1024 pixels that will draw 56.7A max.  The board can handle max of 1024 pixels x 16 output ports.  How can you get to that limit if you only allow max of 5A per output port?  How does power injection comes to play?  How to configure so you can use the max pixels per port without blown the 5A fuses?

Even if the board could handle the reported 57.6 amps for 1024 pixels, there is no way that the wiring of the pixels themselves could handle that much current (nor would you want to have to run 6AWG wire from the controller to the start of the pixel string).  The solution is power injection.  If you really want to run a string of 1024 pixels, figure that you will be injecting power at least 4 places (more may be desired or needed).  The only other solution is to substantially restrict the intensity (as jnealand said in his post) or how you use of the pixels.  For example, if you had created a matrix that you ONLY will use for text, you would be able to use quite a bit more pixels because at any given time, most of the pixels are off.  HOWEVER, I can well imagine that one of these days, you would decide that you were going to make the yard "flash real bright" and be tempted to light up all those pixels with bad results.
Jim

Offline tmarshall

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Re: Power limited to 5A fuses on board. How to use the max pixels per port?
« Reply #3 on: February 13, 2018, 01:02:16 PM »
On the F16v3 board manual https://docs.google.com/document/d/1S67ZVLgQRYsdqPhgfPkQucnFXvu1FmQAME9qnK5RixU/edit last page
stated that for 12v for 50 pixels draw 2.77A and 33.24 watts.  The board maximum pixel per port is 1024 pixels/nodes.  So if my calculation is correct each port cannot connect more than 100 pixels because draw is more that 5A (5.54) and the on board fuse will blown if use white colors with full intensity.  For 1024 pixels that will draw 56.7A max.  The board can handle max of 1024 pixels x 16 output ports.  How can you get to that limit if you only allow max of 5A per output port?  How does power injection comes to play?  How to configure so you can use the max pixels per port without blown the 5A fuses?


Like jnealand said, a lot depends on the pixels you use, and exactly what they draw, but in order to drive all 1024 channels, you will most likely need to use power injection. I setup all of my controller boxes with some distribution boards like the F8 Distro and I create most of my props with power injection pigtails, (whether I end up needing them or not).


There are, however, a couple of options that would almost allow you to max out the 1024 pixel count without power injection.


One is to use the Differential Expansion Boards. Each F16V3 can take two expansion boards, and each expansion board can drive four Differential Receiver boards that you can install in separate enclosures with their own power supplies. The expansion boards effectively add an additional 16 ports each, but they do not increase the total number of pixels you can drive. If you added two expansion boards it would add another 32 ports, for a total of 48, but these ports share their max pixel count with the original set of 16 ports. The 1024 max pixel count would then be divided among sixteen sets of three ports. This has several advantages. not only does it allow you to locate your Differential Receiver enclosures closer to your pixels, but it maximize the number of pixels you can drive without having to resort to power injection.


I am currently building 20 HDPE arches using INK 1003 pixels which internally contain 5V pixels but you drive them with 12V which is stepped down by built-in buck converters. A 5 meter strip contains 300 pixels and draws about 6A on full white. if you dim this just a little, you can easily drive 300 of these pixels off of one port with no power injection. Multiply that by 3 if you using two expansion boards, and you can drive 900 pixels with no power injection, just 124 pixels short of the 1024 maximum.


Another option would be to run a higher voltage out of the controller, and step it down by installing your own buck converters at your props. The F16V3 can handle up to 36V. Power = Voltage * Current, so if you triple the voltage, you reduce the current to 1/3 for the same power. so, if you could connect 100 pixels at 12V, drawing 5A from the controller port, you could, in theory, run 300 pixels using 36V and still not exceed the 5A port fuse rating. Buck converters add cost and complexity. Power injection would be simpler and cheaper, but using buck converters do have some advantages.

 

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