Measuring Voltage and current draws of seed pixels

AussiePhil

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Continuing on from the power injection testing, i thought it might be useful to look at a string of 50 seed pixels

This is a random grab from the ones i have.

All measurements are for 100% brightness, base reading are at 5v, input was raised up to 5.5v for each test to confirm constant current was being used.

Measured the voltage drop on the approx 10 foot of lamp flex from the power supply to the pixel input, it was not negligible and accounted for @ 0.3v drop for white

For 50 Seed Pixels - with voltage end feed
Red at 5v - 280mA, 260mA @ 3.6v
Green at 5v - 280mA, 260mA @ 3.9v
Blue at 5v - 280mA, 260ma @ 3.9v
White at 5v - 740mA, 720mA @ 4.1v

Red 5.6mA per pixel CC
Grn 5.6mA per pixel CC
Blue 5.6mA per pixel CC
White 14.8mA per pixel CC

All four were tested up to 5.5v input with no change to the current draw at 5v

The end voltage on white was a very consistent 1.1v under the input voltage
Colours consistent got 0.4v under

At 100% white plugging another 50 you are already starting under the min voltage required for proper operation.

So end voltages are
100% - 3.93v
90% - 4.03v
80% - 4.13v
70% - 4.23v
60% - 4.33v
50% - 4.44v
40% - 4.54v
30% - 4.64v
20% - 4.74v

Seems that around 50% to 60% you can easy run 100 from one input at 5v. You can get the same at 70% by running the string slightly hot at 5.3v

If you center feed the voltage into the middle of a 100 pixel string you get the same performance 50 pixels each way.

!00% white - 50 pixels, the scope is looking a fraction of the outgoing 2811 data stream

PB210288.jpg

Cheers
Phil
 
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AAH

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What are these seed pixels Phil?
Any chance of doing a 5V vs 12V WS2811 pixel string? With the dual supplies you could have both running on the exact same signal.
Those power supplies look rather sweet and seem to be a rather excellent price. I've added some to my Aliexpress wishlist.
 

AussiePhil

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What are these seed pixels Phil?
Mark beat me to it. they are 6.5x4mm pixels that look like a seed, running standard 2811 likely in slow mode, they also now do other wire colours besides the ones mark linked.
Because the wire is thin they actually approximate the experience you see with normal strings as voltage drop is concerned.
Any chance of doing a 5V vs 12V WS2811 pixel string? With the dual supplies you could have both running on the exact same signal.
Sadly no because i actually don't have any 12v pixels around. it would be interesting to test the two 12v styles resistive and chipped
Those power supplies look rather sweet and seem to be a rather excellent price. I've added some to my Aliexpress wishlist.
The 6012P units got released at the end of October and they are nice, at the moment they are just running from the Manson linear supply on the top shelf until the 1500w 70v SMPS arrives to power them. The red cases are my own 3D printed units

Seed pixels -
PA010235.jpg
 
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