Onumen 5050 waterproof testing

AussiePhil

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Well, it is only a glass of water but it is fully submerged.

This one is a sample that is improved on the first lot that have been around. There is no way i would have even tried this with the first batch i have.

the injection molding is better and extends further along the wires, HOWEVER the molding does not stick between the wires, and in the video you can see a cable tie to hold the wires together and take the strain.

5050 pixel test

Cheers
Phil
 

mrpackethead

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whats the blob of black stuff just above the top of the molding? I have some of these from the factory that makes them for onumen. They might be ok if the wires are not moving..
 

AussiePhil

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Andrew

It's just a 100mm cable tie, holds the wires together and stops them spreading under strain, a fairly cheap workaround to the seperation allowed from the flexible molded plastic.

Think i would still add some waterproofing agent but wanted to see if there would be any seepage from just being in water.
The flexing caused by wind movement would be cause for adding some extra protection.

Still running this morning after 12 hours.

Phil
 

riri7707

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Hi,
If you cut the envelop and keep off the plastic molding, you will see another small layer of resin protecting
the components too upper the 2 pcb boards.

So this double protection increase the waterproof of the pixel.

And even if you see a little space from outside, doesn't means it was not really waterproof...

This cannot be seen if you don't really open one one the pixel to check how it was really made.

For the question of IC : yes this is WS2801, but specific package one very very small and not listed on the datasheet document from WS2801 manufacturer.

Cheers... Henri

Hope this helps...
 

mrpackethead

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on the "onumen" modules i have they are clearly visble from the outside that they are chip on blob. The reason i ask is that i was told ( by a reletively good source ) that the chip on blob variant of the ic is not made by world-semi, but is a rip off the 2801 made by someone else, ( using the same prototocol ). I looked at using this techology as well ( becuase its cheaper ), but my chiense engineers would'nt touch them because of reliablity issues.
 

AussiePhil

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I don't plan to cut this one apart for a while, it is not the normal sized SMD 2801 that is for sure. The first samples did use the normal 2801 SMD IC.
There does appear to be IC legs appearing from under the black sealant.

I went searching for the term "chip on blob" but nothing showed up... got a link i can read?
 

TimW

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Out of interest I cut open an alleged WS2801 8mm led pixel tonight. It is possible they are an inferior copy... but none of mine have failed yet......

My pixels are chip on board I reckon (the blob goes on top of the chip - chip on blob would defeat the purpose :) )

There is some evidence of a conformal coating brushed onto the board as Henri says, but I reckon this will not be enough. The (I assume hand soldered) wires attached to the pixel still have enough metal exposed to suffer if water gets in. So I'm still waterproofing...
 

AussiePhil

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Just a quick update,

after 72 hrs of trying to drown that poor little pixel, It keep going and there was no evidence of any water inside the Pixel.

Now this was just sitting in the glass with no movement caused by wind so real world use may be a little different.

Phil
 
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