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brichi

4amp fuse not enough with 100 nodes

23 posts in this topic

I have a pixie 8 but am only using probably 6 of the outputs for the 6 spiral trees I am making. The trees though are taking 100 nodes each and are drawing 5.5 amps and blowing the 4amp fuse on each channel. Being I am not using all the other channels to the max can I up the fuse size in output 1,2, and 3? I don't know if that fuse rating at 4amp is because that output can't handle more then that size fuse or is it a division of the total controller output so I can up the fuses on 3-4 outputs and lesson them on 3-4 others

thanks!

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This is bad to hear, yet another problem with the pixie products.

JR

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A possible option is to bring power directly to the nodes and tie only the ground, clock and data lines to the Pixie. You'd need to provide your own fuse (an inline auto fuse holder works well) in this case.

-Gary-

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that true, I can send the +- right from the p/s into the connectors I'm making to feed the tree and bypass the controller, just send the data wire from the controller or I can break up the strings and do 50 nodes per output so 1 tree is out 1 and 2 but that annoying when programming obviously. I think if I put a 7 amp fuse in out 1-3 and then don't use 4 on that side ill be fine. then tree 4,5 and 6 can run off the other side of the pixie8 being they're smaller and not pulling more then like 3 amps each

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46 minutes ago, dibblejr said:

This is bad to hear, yet another problem with the pixie products.

JR

How is exceeding  the per channel design spec make  the Pixie BAD? (that 4A  spec seems typical for controllers  from what I see)

The user configuration is sub-optimal if I understand the original description.

If the load is near continuous, the 80% rule (3.2A) applies for fuse integrity... Power injection is recommended at >50 node for 5V.

Considering the comment on ease of programming, power injection at mid point seems to be the prime choice.fuse blocks are fairly cheap compared to repeated blown fuses.

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thanks TheDucks, injecting half way is probably what I will do or just run the power right from the p/s with a 7amp fuse

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1 hour ago, TheDucks said:

How is exceeding  the per channel design spec make  the Pixie BAD? (that 4A  spec seems typical for controllers  from what I see)

The user configuration is sub-optimal if I understand the original description.

If the load is near continuous, the 80% rule (3.2A) applies for fuse integrity... Power injection is recommended at >50 node for 5V.

Considering the comment on ease of programming, power injection at mid point seems to be the prime choice.fuse blocks are fairly cheap compared to repeated blown fuses.

I guess I fail to see where Brichi says he has 5V pixels. I also know what is advertised up to 100 pixels per string. So they should come prepared to accept the appropriate amperage for 5 or 12V. And the fuse for the correct amperage.

Maybe you don't follow that there are issues with at least the pixie16's and a firmware update is in the works and that they are seeking Beta testers for said pixie16's. I do because I have 2 of them.

"8 String smart pixel controller

  • Up to 100 pixels per string"

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Welcome to the world of power injection.  Nothing unusual about this.

 

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1 minute ago, k6ccc said:

Welcome to the world of power injection.  Nothing unusual about this.

 

I sure am glad mine are 12v and I am only using 50 on each channel. One less problem

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Power injection is not that big of a deal.  I'm running power injection in several places in my year round landscape lighting,and there will be some more when I finally finish that project.  And just because running at 12V vs 5V does not make you immune to voltage drop.  I will happily tell my story about 30 feet of 12V WS2811 strips and the measurements I did that resulted in me adding power injection.

 

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6 hours ago, k6ccc said:

Power injection is not that big of a deal.  I'm running power injection in several places in my year round landscape lighting,and there will be some more when I finally finish that project.  And just because running at 12V vs 5V does not make you immune to voltage drop.  I will happily tell my story about 30 feet of 12V WS2811 strips and the measurements I did that resulted in me adding power injection.

 

Jim, I am keeping mine simple. Just my matrix and tree being added until I can get a grasp. I like to buy things that are almost truly P&P that's why I got the 16's just to find out they are not as P&P as the AC controllers.

I think with my 50 nodes per strand with their own channel and the controllers affixed to the prop I will not need PI (I hope)

But you know I always read your posts because they are always full of knowledge that will be useful to everyone.

JR

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yes, I'm doing 12v 100 node string, ill just send the power right from the p/s, its easy to do obviously, ill just bypass the controller power

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14 hours ago, dibblejr said:

This is bad to hear, yet another problem with the pixie products.

JR

Are you SURE this isn't maybe an issue with the pixels the OP is using?  4A @ 12V is pretty much standard for 100 pixels.  If this persons pixels are drawing more than that, then they are higher power than the Pixie (or really almost ALL) pixel controllers can handle. That does NOT mean the pixels the OP is using are BAD in any way -- I am sure I can find a string of FIVE pixels that can exceede 4A at ANY voltage if I look hard enough.  Do not confuse being able to POWER something with being able to CONTROL something.

Blaming the Pixie is like plugging your range into a standard 15A outlet and then blaming the range for tripping the breaker -- or burning down the house.

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the pixels are not bad they just draw a lot i guess, the string is rated at and drawing 5.5 amps when on white, i bought 10 of them, all the same amp draw

 

https://www.aliexpress.com/item/100pcs-DC12V-addressable-12mm-WS2811-led-smart-pixel-node-with-all-WHITE-wire-20AWG-IP68-rated/32278099262.html?spm=2114.13010208.99999999.264.we2Hyy

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41 minutes ago, DevMike said:

Are you SURE this isn't maybe an issue with the pixels the OP is using?  4A @ 12V is pretty much standard for 100 pixels.  If this persons pixels are drawing more than that, then they are higher power than the Pixie (or really almost ALL) pixel controllers can handle. That does NOT mean the pixels the OP is using are BAD in any way -- I am sure I can find a string of FIVE pixels that can exceede 4A at ANY voltage if I look hard enough.  Do not confuse being able to POWER something with being able to CONTROL something.

Blaming the Pixie is like plugging your range into a standard 15A outlet and then blaming the range for tripping the breaker -- or burning down the house.

I would have to disagree with this statement. For the most part WS2811 50 node strings are on average 2.2 amps and most of the controllers out there have 5 amp ports. The only controllers with 4 amp ports that I know of are LOR's Pixies, Pixcon and the Pixlite. The Sandevices, Alphapix, Falcon, Hinkspix and most others are 5 amp.

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1 hour ago, DevMike said:

Are you SURE this isn't maybe an issue with the pixels the OP is using?  4A @ 12V is pretty much standard for 100 pixels.  If this persons pixels are drawing more than that, then they are higher power than the Pixie (or really almost ALL) pixel controllers can handle. That does NOT mean the pixels the OP is using are BAD in any way -- I am sure I can find a string of FIVE pixels that can exceede 4A at ANY voltage if I look hard enough.  Do not confuse being able to POWER something with being able to CONTROL something.

Blaming the Pixie is like plugging your range into a standard 15A outlet and then blaming the range for tripping the breaker -- or burning down the house.

Mike, I was going by the other two problems I had. Both of which you addressed, 1 -I took care of (the screw connectors on the wire harness's screw counter clockwise to secure)  the other (firmware update) is being addressed and asked for Beta testers in the other thread. The latter of the two I cant attempt until my matrix is ready.

May I ask though, are the P&P pixie16 with the nodes setup needing the same updates or are they ready to go. I know it says P&P, just asking. I may go down that route if for my tree if they go on sale.

Thanks

JR

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9 minutes ago, Mr. P said:

I would have to disagree with this statement. For the most part WS2811 50 node strings are on average 2.2 amps and most of the controllers out there have 5 amp ports. The only controllers with 4 amp ports that I know of are LOR's Pixies, Pixcon and the Pixlite. The Sandevices, Alphapix, Falcon, Hinkspix and most others are 5 amp.

My point is still valid however even in light of those other boards - if the OPs pixels draw 5.5A, he is going to blow the fuses on THOSE boards as well if they are 5A.  

You are also confusing LED Driver with the draw of the LED.  The chipset used to drive the LEDs (in your example, 2811) is not the limiting factor here.  The only thing different chipsets have is different on-wire data protocols.  For any given RGB LED that is attached to a driver chip, the draw will be identical regardless of that chipset.  That is to say that the total amp draw of a single RGB LED attached to a 2811 driver is going to be identical if that same RGB LED is attached to a 2801, or Stellascapes, or whatever other LED driver is out there.

As I said, I am also sure I can find a 2811 'string' that consumes more than 4A with only 5 pixels at some arbitrary voltage.  I'm also sure I can find a 2811 string that has more than 100 pixels and draws less than 4A at that same voltage.

Of all the manufacturers we consulted with, 3.8A per string (which we round up to 4) was common for just about ANY common voltage (5/12/24/48).  For 5V strings, that was 50 pixels, for 12V strings, that was 100.  Once you get past 12V, other factors come into play which make things cost prohibitive, even though those higher voltages have some significant upside.

I can back all this up with specs from our current pixel offerings and a little math:  Our 5V pixel strings (50 count) consume just under 3.8A.  Since we know that A=W/V it stands to reason that if we double V, then we can also double W and still have the same A.  In other words, at 5V 50 pixels consume 20 Watts (4=20/5).  At 12V it should be expected that 50 pixels with identical output specifications still consume 20 Watts -- but that translates to 2A (actually 20/12 = 1.6A).  100 pixels @ 12 V being 4A or less.  Again, this is also the sweet spot for cost.

Where you may be confused is that many of those boards are concerned more with DMX than we are.  For them, a fully loaded universe is 170 pixels.  SO sticking with 12V, we can extrapolate.  If 100 pixels @ 12V is 3.2A, then 170 pixels (510 channels - a full DMX universe) comes in around 5.4A.

This is the reason the PixCon is rated to 6A per port.  Yes, it does ship with 4A fuses since we want to be standard with the rest of our offerings.  We do however support replacing the 4A fuses with 6A ones on that board (but not Pixies).  We don't publicize that since we are afraid people will start swapping fuses on EVERYTHING, but you can.

The blame does not rest with the board NOR with the pixels.  The blame rests with trying to draw more amps from a circuit than that circuit is designed to allow.

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so devmike, can up up the fuse on port 1-3 if I'm not going to use some of the other ports? not sure if the amp calculation is due to the entire output of the board or port 1 really can only hold 4 amps

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Some of the limit is about the Trace that feeds the fuse.

From the manual: ports 1 and 5 are closest to the feed. If I was assigning channel loads, those would be the highest

 

But I think you are trying to avoid the bigger issue. VOLTAGE DROP

You seem to insist on pushing the entire load from the end. Pixel 100 is going to have the lowest voltage normally.  With a string that draws 125%  of typical, either the wire size needs to get bigger or you  cut the + somewhere near mid point and inject Fresh power for the rest

IMHO   http://www.doityourselfchristmas.com/wiki/index.php?title=Power_Injection has a really good set of diagrams and explanation

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Posted (edited)

the tree looks great though without injecting so I'm not sure why i would need to if i can get away with just pushing from 1 end with a 6 amp fuse off the board of p/s vs 4

 

tree -  

 

Edited by brichi

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1 hour ago, brichi said:

can up up the fuse on port 1-3 if I'm not going to use some of the other ports? not sure if the amp calculation is due to the entire output of the board or port 1 really can only hold 4 amps

No you can not.

1 hour ago, DevMike said:

We do however support replacing the 4A fuses with 6A ones on that board (but not Pixies).

Like 'The Ducks' said, there is more to it - like trace width, copper weight (thickness), etc.  Pixies are not rated for more than 4A per port.  You need to either power inject (which we do not officially support), or use pixels that are within the spec of the board.

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1 hour ago, brichi said:

the tree looks great though without injecting so I'm not sure why i would need to if i can get away with just pushing from 1 end with a 6 amp fuse off the board of p/s vs 4

 

tree -

 

Pretty awesome.

Run 2 wires up to the halfway point and inject. You can even use the same PSU that feeds the Pixie (if it has enough headroom left. Running anything Electronic at 100% is not good for longevity)

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I'm going to inject at the top of the tree, I cut at 50 nodes the +and- and then I can run a wire hidden up the support pole to the top and power from up there for the remaining 50. getting a fuse block tomorrow so its all fused

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