12V Resistor and 12V Regulated WS2811 Pixels

David_AVD

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One thing you may have not considered is that there is a newer style of 12V pixel that has the 3 LEDs in series, with controlled shunts across each LED. Off the top of my head they are GS82xx series, but I could be wrong. They've been talked about on this forum. Those pixels don't give you the usual R + G + B current figures you're expecting.
 

TerryK

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You are not wrong David, you're thinking of the Genesis Systech GS8206 and GS8208 I believe. There is some ACL Wiki information on those and you and I have both discussed them in other posts. Best as I can determine the WS2815 uses a similar design. I have some test data on the 2815s, just not ready to post it yet; sometime 2021 hopefully.
 

i13

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There are some 12V pixels that run at 10mA per node to reduce the current and therefore the voltage drop and power consumption. It is explained in one of the threads that I linked to. This is done at the expense of brightness. The human eye doesn't have a linear response to brightness so the difference appears less than you'd expect.
 

Indigogyre

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There are some 12V pixels that run at 10mA per node to reduce the current and therefore the voltage drop and power consumption. It is explained in one of the threads that I linked to. This is done at the expense of brightness. The human eye doesn't have a linear response to brightness so the difference appears less than you'd expect.
There is some irony in that you would loose brightness but with less power draw could run them at a higher brightness setting then the normal ones which everyone seems to run around 30%. With a higher brightness setting overall you could get better color mixing to my understanding.
 

MichaelF5

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Life is not without a sense of irony.. I'm a bit surprised that the Regulator is so inefficient that running the resistor is better....

Looking at White, 5v is doing 410 mw, 12resistor 370mw, 12 Reg 596mw

so this is due to the Resistor reducing the amount of current wattage available for the node, so in theory it can't be as bright, as per Indigo, not sounding like an issue for many?
 

TerryK

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Bit puzzled, might I ask where you obtained the 410 mWatt? That should be I think in the 240 mW range.

It's not that the regulated 12 Volt pixel is so much more inefficient but rather that it works better in some displays than 5 Volt or 12 Volt Resistor pixels. Notably because the regulator allows the pixel to maintain color and illumination over greater distances. From what I have tested a WS2811 regulated 12 Volt pixel will work reasonably well down to somewhere around 5 Volt where the regulator is beginning to drop out of regulation. A 5 Volt pixel somewhere around 4 Volt and a 12 Volt Resistor pixel in the 10 Volt range. Pixels, like tools need to be properly applied to get the best use from them.

The resistors are I think more of an attempt to have a 5 Volt device work on 12 Volt without destroying it and biasing it properly to have it function as intended. For a WS2811 device anyway. Another point; some time back, Mark emailed me a schematic of the pixel he dissected. That pixel's internals (schematic) had different component values than the pixel I examined. Mine came from Wired Watts. His, I do not know. Point is, different manufacturers can and do build in variances within the same pixel 'family'. Comparisons are not always straight-forwarded.
 

MichaelF5

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Bit puzzled, might I ask where you obtained the 410 mWatt? That should be I think in the 240 mW range.

It's not that the regulated 12 Volt pixel is so much more inefficient but rather that it works better in some displays than 5 Volt or 12 Volt Resistor pixels. Notably because the regulator allows the pixel to maintain color and illumination over greater distances. From what I have tested a WS2811 regulated 12 Volt pixel will work reasonably well down to somewhere around 5 Volt where the regulator is beginning to drop out of regulation. A 5 Volt pixel somewhere around 4 Volt and a 12 Volt Resistor pixel in the 10 Volt range. Pixels, like tools need to be properly applied to get the best use from them.

The resistors are I think more of an attempt to have a 5 Volt device work on 12 Volt without destroying it and biasing it properly to have it function as intended. For a WS2811 device anyway. Another point; some time back, Mark emailed me a schematic of the pixel he dissected. That pixel's internals (schematic) had different component values than the pixel I examined. Mine came from Wired Watts. His, I do not know. Point is, different manufacturers can and do build in variances within the same pixel 'family'. Comparisons are not always straight-forwarded.
Your attached correction sheet https://auschristmaslighting.com/th...12v-regulated-ws2811-pixels.12161/post-114862

Was under the impression you guys measured?

reducing the number of injections required to run to each set is my goal basically, I'm not that fussed if they are that inefficient unless it effects the amount of pixels able to be run from a single ended string, are they still making these sets... anyone pumped the voltage up high enough to see how the reg survives?
 

TerryK

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Fooey. OK, I finally see it. Me when I edited the 5 Volt chart to correct the calculation, somehow left the original posted erroneous 5 Volt chart png attachment in the Thread Post. Clicking on the attachment opened the incorrect png.

Your question: Yes, voltages and currents are/were measured. If you want to reduce the number of injection points I would I think use the Regulated 12 Volt pixels. Thought being to allow (assuming 12 Volt at the injection point) a large voltage drop down the string to an approximate 5 Volt at the last pixel. Center pixel if you feed double-ended. From the WS2811s 12 Volt Regulated I have tested they drive reasonably well down to that voltage. Drive levels, colors, and wire gauge are variables that would need looked at. I do need to say I have not tried doing that. So far I inject power at numerous locations essentially moving voltage drop into the power injection cable. Say for example, feed a 12 Volt Regulated prop with 8 Volts at multiple locations and allow the 12 to 8 volt drop in the power injection cable.

Someone may have raised the voltage to 'exercise' the regulator but I have not and see no point in doing so. Functioning properly it will regulate until its operational characteristics are exceeded causing it to fail or shut down in the attempt to protect itself. These are (what quickly comes to mind) Vin exceeded, Iout exceeded, or internal power dissipation too high.

Certain 'factors' are I think easily over-looked. Ignoring voltage limitations and resistor/regulated, say one has a WS2811 and it is pulling about 20 mA. At 5 Volt that's 100 mW but at 12 Volt 240 mW, where does that extra wattage go in a 12 Volt pixel? The non-light 140 mW does nothing more than add more heat to the pixel. I think 30 Volts or so was asked in another Thread. Extra wattage at 30 Volts would be 500 mW ([30 - 5] * 20).
 

480hsv

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Hi All.

Last year was my first show and i purchased regulated pixels.

If i were to add to my show this year, can i purchase resister or do i need to stick with regulated?

I plan on adding strands to my megatree and adding new props. Also if i need to replace pixels etc, do i need to stick to the same type or can i mix and match?
 

Adsy

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yes you can mix and match i did last year . As long as it sees the same voltage job done but i'm sure someone else will give a more detailed view
 

Notenoughlights

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I've got a mix and match of resistor and regulated pixels, from many different vendors and have not run into any difficulties doing such. Just make sure the voltages match, i.e 5v with 5v and not 5v with 12v.
 

480hsv

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I've got a mix and match of resistor and regulated pixels, from many different vendors and have not run into any difficulties doing such. Just make sure the voltages match, i.e 5v with 5v and not 5v with 12v.
Great thankyou for the clarification.
 

i13

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I don't want to get too far off of the original topic here but you can run 5V and 12V pixels end-to-end. You would just cut the positive wire where the voltage changes and you'd power the second voltage (furthest from the controller) using power injection.

I'm not that fussed if they are that inefficient unless it effects the amount of pixels able to be run from a single ended string
Using the 12V regulated pixels would maximise the number of pixels that you can run end-to-end without power injection. The tradeoff is that having pixels that consume more power per pixel would reduce the number of pixels per power supply before you max it out.
 

MichaelF5

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I don't want to get too far off of the original topic here but you can run 5V and 12V pixels end-to-end. You would just cut the positive wire where the voltage changes and you'd power the second voltage (furthest from the controller) using power injection.


Using the 12V regulated pixels would maximise the number of pixels that you can run end-to-end without power injection. The tradeoff is that having pixels that consume more power per pixel would reduce the number of pixels per power supply before you max it out.
it's somewhat worse than that from my understanding, by the sounds of it (and someone would need to do some testing) the increased load each pixel uses would greatly impact the load the wire can handle.. so I'd not be surprised if you don't get much further at all.
from my basic reading of the diagram of a Buck Reg (the one that they are using to drop the voltage from 12v for the 5v pixels) they are basically dumping the excess voltage to ground, so depending on the voltage and so fourth the draw would make each pixel looks like they have the draw of two.. again I'd love to see data on this to understand just how bad it is.
 

TerryK

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it's somewhat worse than that from my understanding, by the sounds of it (and someone would need to do some testing) the increased load each pixel uses would greatly impact the load the wire can handle.. so I'd not be surprised if you don't get much further at all.
from my basic reading of the diagram of a Buck Reg (the one that they are using to drop the voltage from 12v for the 5v pixels) they are basically dumping the excess voltage to ground, so depending on the voltage and so fourth the draw would make each pixel looks like they have the draw of two.. again I'd love to see data on this to understand just how bad it is.
Worse? Not really. Load is a rather vague term. Defined in Watts, yes a 12 Volt Regulated WS2811 pixel uses/causes a higher load than a 5 Volt WS2811 pixel. Defined in amperage then no. A 12 Volt WS2811 pixel at full white draws about 50 mA which is about the same amperage as a 5 Volt WS2811 at full white.

So I disagree. 12 Volt Regulated (versus a 5 Volt) pixels do not effect the load (in amps) that a wire can carry. 12 Volt Resistor pixels have a different design so they are somewhat 'a horse of a different color' sitting in the 30 to 40 mA full white essentially better than either a 5 Volt or 12 Volt Regulated pixel. Wires by the way do not care about Watts. Amperage is the primary factor. Wire resistivity is a constant based on the type and gauge of the wire. Watts 'burnt' in the wire and voltage drop across wire points are then only calculated values.

The power source though does care. Using a Meanwell supply as an example, their 5 Volt 60 Amp supply would need boosted to a 720 Watt if the pixels were swapped out to 12 Volt Regulated pixels. As @i13 mentioned, the number of pixels drop per supply as the pixel Wattage increases. A comparison of a LRS-350-5 to a LRS-320-12 easily shows this. Voltage goes up then available amperage goes down.

Buck converters do not dump anything to ground. It is better to think of them as a small switching power supply; similar to say to the LRS-320-xx only much, much lower in wattage output and without the AC frontend.
 
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