Planning power for megatree

Kurt87

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Just a quick one for the gurus. I’m currently building my controller for my megatree and just had a question regarding planning for 100% brightness or not. I know ideally it would be great to over engineer the system to run at its max but I plan on only running at 30%. The only reason I’m wary is because Iv read that sometimes if there is a data issue it can default to 100% brightness therefore potentially overloading the supply and/or blow some fuses in the process. Basically what is the likelihood if I set the brightness on the actual falcon ( not xlights ) to 30% that it would corrupt. Has anyone experienced this?

My setup ...
Tree - 24 strands x 100 + ~100 for star
Controller - F16v3 w/expansion
Pixels - 12v regulated
Power - (planned) 2 x 12v LRS-350-12

Hope this makes sense. Thanks in advance
 

TerryK

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I too would not be concerned about an inadvertent change in the maximum illumination setting. Just insure that the display is properly fused. Fuses are protection for unplanned events; hardware and/or software related.

If you have not yet viewed the Bill Porter Power Injection video I would recommend watching it.
 

Kurt87

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Thanks for the reply terry. I have watched the vid a little while ago, I was just throwing it out there to see if anyone had any issues and if so.... how frequent. id just seen a few posts of people saying to design for 100%. It would be more likely my setup wouldn’t blow fuses but overload the power supplies
 

TerryK

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You are welcome. I know some individuals design for 100%, others lower. 30% is mentioned rather often. I target the pixels at 80% and then design cables and power supplies to be able to drive to that target.

Supplies as one could expect have different capabilities. Meanwell's LRS series is popular but I do not use them because their overload mode is what Meanwell calls a 'Hiccup' mode. I use Meanwell's RSP supplies which enter current limit on overload. My preference is I would rather 'brown-out' the display on an overload rather than shut the display down and attempt a restart. However, fusing should open before the supplies enter overload (if I engineered the display correctly).
 

Jorge Bolivar

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Hello @Kurt87
Once the controller (Falcon) its set to an specific brightness unless you directly instruct the change and save it, it will not going to change on its own. Things can always happens but before this called bugs occurs it is a fat finger touching what it should not be.

Answering your question:
I do make some test and never see the brightness changes not even lost the channel output parameters. Now when I test auto upload I experiment some changes because during this procedures we are authorizing the sequencer to override the controller data. This is what I do think generate those comments.
In my opinion controller should not be auto-programmed so I do stick with what i do fell comfortable.

Protect your assets from overload using fuses, fuses protects your wiring (therefore your equipment) and blew up before PSU overloads occurs.
 

Kurt87

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Thanks for the replies gents. Yes I will have fuses to protect my cabling ( people often think fuses are there to protect your equipment but it’s job is to protect the cabling ) and also correct about the fat fingers causing havoc. I would be interested to know if anyone has had any experience with overloading the LRS model power supplies and how they behave ie; hard shut down? / resets on its own? / internal fuses blow if any? One of the first things I was taught with electronics many a moon ago was just don’t let the smoke out : )

I think I will have room to add an extra power supply in my enclosure so that will allow me to run at up to around 60%
 

i13

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Going by the specifications sheet, the Mean Well LRS-350-12 power supply's overload protection is "Hiccup mode, recovers automatically after fault condition is removed." I've accidentally shorted the output of my SP-320-27 power supply (a discontinued model) when I left the multimeter on the current measurement setting instead of voltage measurement. The power supply hiccupped without blowing the multimeter's 10A fuse.

If you find them at a similar price, I'd recommend the RSP power supply over the LRS. The power factor correction means you can come closer to the load limit without your circuit breaker tripping. It might not matter immediately but it could come back and bite you later as your display grows. Here's a thread that explains it https://auschristmaslighting.com/threads/6365/
 
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