12V Resistor and 12V Regulated WS2811 Pixels

Mark_M

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That is a spoiler. I had hoped that something more exotic was used. Low quiescent and low dropout. About a 3mA quiescent on top of the already inefficient design :jawdrop:

I won't bother with the test. Just let it release the magic smoke then :). LOL.
 

AAH

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Mark, are you sure about the regulator number? That's what you saw printed on it?
I presumed that it was a 78L05 which has the 3mA quiescent compared to the 7805 which is 5mA. With Chinese components the marking could be anything of course.
 

Mark_M

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After much delay trying to find a thermocouple to test heat extremities I decided not to perform the test :(.
This video is just the lowest voltage dropout.

I'd be interested to see what the quiescent/standby current of the pixel is with both no data going through
Damn it! I didn't measure without data....



If you cannot be bothered to watch this video.... Spoiler!
Spoiler content hidden. Log in to see this content.

If you have a spare 12 minutes, here is the test video.
Manually edited captions are available (with bad spelling :)).
(Edit: A few spelling mistakes in the video too! It's a majour disappointment. Can they add spell check to a video editor please?)
View: https://youtu.be/n0ZBYLhwcIA


In the video: 'Inside the voltage regulator there is a 78L05 voltage regulator', 'power supply outputting a constant 12v' and 'Sir Circuit'
LMAO!!


No temperature measurements or magic smoke sadly. Once I get some thermal cutout measurement I'll blow it up :).

Spoiler: Specified highest voltage:
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^ According to Texas Instruments data sheet.
https://www.ti.com/lit/ds/symlink/lm78l.pdf (Not an accurate data sheet for this component.)
Bit more accurate to this regulator: https://pdf1.alldatasheet.com/datasheet-pdf/view/22687/STMICROELECTRONICS/78L05.html
 
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AAH

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The future IS now. lol
I kept looking at the meter doing the current measurements and thinking "Mark, change scales".
Your video production is much better then mine. As a result of that I now have Davinci Resolve on my "to do" list to try to see if it makes my video production any better.
It's a shame that the camera was white balancing automatically and not showing the change in colours.
Overall an excellent set of tests Mark and I'm actually a little surprised at how well the 78L05 performed.
 

Mark_M

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The future IS now.
I was trying to find the commentator voice from the computer game Portal 2. "At Aperture laboratories the future is now.".
I managed to find something similar but not the full audio clips of the game. The website seems to have been taken down..... :(

I kept looking at the meter doing the current measurements and thinking "Mark, change scales".
What other scales lol?
The Fluke 23 (1980's model) only has DC current and it auto selects decimal point. I had the probe in 300mA range.

Your video production is much better then mine. As a result of that I now have Davinci Resolve on my "to do" list to try to see if it makes my video production any better.
There is a paid version and free version. It is a bit tricky to learn... I like tracking elements in it. E.g. blur faces moving. I haven't learn't 'node' level yet!
View: https://youtu.be/GmHAiUcAPwk?t=73
 
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bpratt

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So the easiest way to identify regulated versus resistor pixels is ???

I'm sure there's a few of us that may not be able to determine what they already have.


Would it be safe to assume that you could run both types if you can guarantee you've got 11.9v getting to all of your pixels ?
 

Mark_M

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So the easiest way to identify regulated versus resistor pixels is ???
I'm sure there's a few of us that may not be able to determine what they already have.
Would it be safe to assume that you could run both types if you can guarantee you've got 11.9v getting to all of your pixels ?
LDL's first post has a link to WiredWatts with images on each type.

You can certainly use both safely, you just might experience brightness problems.
 

AAH

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So the easiest way to identify regulated versus resistor pixels is ???

I'm sure there's a few of us that may not be able to determine what they already have.


Would it be safe to assume that you could run both types if you can guarantee you've got 11.9v getting to all of your pixels ?
On https://www.wiredwatts.com/learn-regulators there's pics of the resistor and regulator pixels. The resistor 12V ones have 3 matching sized resistors on the back of the pcb. The regulator style 12V have a regulator and 2 tiny capacitors on the back. It has the 8 pin pixel IC on one side of the pcb and a 4 pin regulator on the opposite.
 

drakky

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so is anyone using a mix of the 2 types ? is it noticeable any differences in the brightness or colours ?
 

TerryK

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so is anyone using a mix of the 2 types ? is it noticeable any differences in the brightness or colours ?
This will be a mix of subtle variations in the pixels themselves (very difficult to determine with a naked eye I would think and impossible to avoid in the manufacturing process) and how well the display IC handles IR (voltage) drops. While I would avoid a mix of 18 AWG and 20 AWG (or 22 AWG) pixels within the same prop, a mixture of resistor and regulated pixels should not be noticeable providing that drive level caused voltage drops remain below the illumination threshold. To help explain, if one sets a particular drive level and slowly lowers the supply level, a 'knee' will be reached where illumination rapidly begins to decrease. A lower drive level has a lower 'knee'. I've tested white, not quite sure what happens say blue versus green.

For white, 90% drive a resistor pixel' threshold is pretty close to 11.1 Volt, regulated approximately 5.4 Volt. These values are from 18 AWG WS2811s from Wired Watts. At 75% white drive the resistor drops to 10.3 Volt and the regulated to 5.0 Volt. The small change in the regulated pixels is the regulator IC falling out of its capable range. Also shown is how well the PWM and constant current RGB outputs do driving the LED.

Oh. and before anyone mentiones it, yes, one does need to be a bit off their rocker to go to this much trouble. Cheers.
 
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