smart versus dumb pixel cost example - Twig/stick trees

nutz4lights

nutz4lights

Full time elf
Joined
Dec 12, 2012
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Location
Melbourne, Florida
Hello Aussie Lights folks...

First post here, so I figured I'd make it a doozy. Making my way here from Planet Christmas because of the resident experts in the field of RGB lights, which is something of interest to me... Was over at Planet Christmas since probably 2006-ish. Been an LOR user my entire time in this crazy hobby... looking to jump into either dumb pixels with LOR DC or smart pixels with E1.31 from J1SYS... Wanted to add that, although I've never been to Australia, my wife and I did make it most of the way there (Fiji) for our honeymoon and our interactions with all the vacationing Aussies was a good one... top notch nice folks.

My question (up front) is that I have read topics mentioning that the cost of dumb pixel setups starts to approach just going with a smart pixel setup for some applications. It kind of blew my mind because the cost of the smart pixels is nearly 2X that of the dumb pixels from Ray Wu. One area where I've seriously considered doing RGB is on my plethora of wire/stick/twig trees, so I thought I would try to work through the numbers and see which made sense. I'm hoping that folks here can go through this and make sure I have a good grasp on this because the smart pixel option is more than 50% more for this application by my calculation.

So, for years we have used a bunch of the twig, stick, wire trees. I had around 10-15 of them and then last year after Christmas managed to pick up another dozen or so on sale at Sears. For anybody that is unfamiliar, they look like this:

http://www.sears.com/shc/s/p_10153_12605_07111040000P?vName=Seasonal&cName=Christmas&sName=Outdoor%20Decorations%20&%20Figuresmv=rr

They typically come with anywhere from 300-600 lights depending on height. So, for years I have taken the 400 or 600 light versions I have and added a comparable amount of red and green. The lights are too heavy and it makes the twig branches bend (they are flimsy metal) and over time they break. I thought it would be great to replace the three color strings with a single string of RGB pixels, greatly extending the longevity of the trees before the branches are all busted. I am going to use 400 lights per tree in the example below, which would probably end up getting reduced, but at least I am comparing apples to apples.

Some things I am assuming:

- three trees per LOR controller is because of current draw (1200 nodes x 0.3W = 360W and a fourth tree would absolutely max out the LOR controller's 480W rating for 12V @ 40A)
- two trees per J1SYS ECG-P2 controller is because each tree would be four universes of 100 pixels each and there are two channels of four universe capability on the P2 the way I'm reading it)

Dumb RGB Pixel Approach (using 12 trees to most efficiently use LOR controller)

400 nodes x 12 = 4800 nodes @ $0.25 per node = $1200
each LOR controller can do three trees so 4 x $99 = $400
each LOR controller needs dual 240W power supplies so 8 x $20 = $160
each LOR controller needs some form of casing for the controller and power supplies so 4 x $50 = $200

Total = $1200 + $400 + $160 + $200 = $1960


Smart RGB Pixel Approach (using 12 trees to most efficiently use J1SYS controller)

400 nodes x 12 = 4800 nodes @ $0.45 per node = $2160
each J1SYS ECG-P2 controller can do two trees so 6 x $68 = $410
each J1SYS ECG-P2 controller needs a 360W power supplies so 6 x $25 = $150
each J1SYS ECG-P2 controller needs some form of casing for the controller and power supplies so 6 x $50 = $300

Total = $2160 + $410 + $150 + $300 = $3020

So, did I do the above math correctly? I think the smart pixel approach would be very cool because the shimmering of individual pixels on the trees would look great! The thing is for $1100 extra... I could build up a megatree with smart pixels based on Fast Eddy's design...

Thanks for the comments / dialogue! I appreciate it.

-Louie in Melbourne... Florida
<yes, I really live in Melbourne, FL, and its not nearly as nice as the pictures I've seen of Melbourne Australia
 
Here is rays pricing:



Ray's 2811 is $17 for 50
http://www.aliexpress.com/item/promotion-12mm-RGB-full-LED-pixel-module-WS-2811IC-DC5V-input-50pcs-a-string-IP68-led/564836955.html


vs $12 for 50
http://www.aliexpress.com/store/product/IP68-DC5V-input-12mm-through-hole-LED-channel-letter-RGB-color-50pcs-a-string/701799_522237021.html


When you add in delivery (which may cost more then the nodes themselves), the cost difference is negligible between ic and non-ic nodes.


I wish I had bought the 2811 nodes for my minitrees!


Also the thing to note is the nodes are VERY bright, my minitrees only need 100 nodes each vs 200-300 for traditional LED strings (see them here https://vimeo.com/kristmas).
 
You will definetly get away with less pixels than using traditional lights. I reakon you could use 1/2 of what you used to with traditional lights and still end up with a more effective tree than in the past
 
Thanks guys. I guess I was looking at the 12V strings so that I could more easily tie in strings of 100 without injecting power. Also, are the 2811 fair game with the J1SYS products? I need to read again, but I thought that was not the case yet. I thought we had to use 2801.

I've been saying this for a year now (to my defense, we did move in the last year and had our third son)... but what I need to do is get one of these trees unboxed and order 400 pixels to see if I am happy with 200, 300, etc...

Thanks again,

-Louie
 
2811 is supported on all the j1sys controllers and works very well (I only have 2811 in my display).


How often you need to inject power is best left to your own testing, I am using the 12v 2811 strip and have to inject power every 50-70 pixels, some others will have ideas on power injection for 5v nodes.


You have given yourself heaps of time, so keep posting questions and the results of your tests and we will keep helping (and at times learning from) you.
 
That is great news on the 2811 and J1SYS, I had missed that in my reading.

That is a bummer on having to inject power every 50-70 pixels even on the 12V. For some odd reason (again, I've been reading so much that I'm having trouble digesting every piece of information) I thought that the one benefit of 12V was to support strings 100-125 pixels without power injection. I thought the 50-70 number was more in lines with the use of 5V bulbs.

I said it, and you agreed, one simple way to do it is get some pixels and test and I will try to do that early next year.

-Louie
 
nutz4lights said:
That is a bummer on having to inject power every 50-70 pixels even on the 12V. For some odd reason (again, I've been reading so much that I'm having trouble digesting every piece of information) I thought that the one benefit of 12V was to support strings 100-125 pixels without power injection. I thought the 50-70 number was more in lines with the use of 5V bulbs.
Click to expand...

I've found that with the 12v 1804 pixel strings that I use (as opposed to strip) , I'm able to be run with 100 pixels with no noticable fading at the end of the string (with no power injection, even at the end).. I'm pretty sure that the 5v pixel strings cannot do this, so you're on the right track with thinking that 5V suffers more from voltage drop.

With the pixel strip, each pixel is actually three 5050 LED's, so each pixel is drawing nearly three times the current, so you'll probably find that you get less mileage... But, in my case, the maximum I've gone to with 12v 2801 strip is 13.5metres of strip (161 pixels), with voltage injection at the end, as well as approximately halfway (after 90 pixels).

But as you say - best to get some and test them out to see what works for you.. Unfortunately things seem to vary a bit!!
 
The fact that you are making a tree and adding the lights to the braches and trunk means injecting power should be very easy. After the first say ~70 pixels just run a feed up the trunk to wherever you are up to. If your feed is big enough it can just be continued up the trunk from the start of string to the second injection point. Actually easier than most cases when injecting power is needed.

Cheers,
Rowan
 
Now keep in mind that i'm a newbie so i'm still trying to figure this out. but wouldn't this controller cost you half what you r looking at and save you on power supplies? http://www.j1sys.com/ecg-p12r/
I also may believe that there is more DC options that could drive the cost down.
Keep in mind i'm still trying to figure tis all out myselfSo if i'm wrong someone please jump in here.
 
One important factor that will determine how much power injection is required is how far away the lights are from the power supply. Thed amount of lights that can be run will vary depending on this because in many situations you could find that you have already lost over 1 volt when the lights are on. Using one colour may not show any difference and even 2 colours, but if going white then this could easily show with the end of the string becoming pinkish. So your initial volatge drop will be dertermined by the cable guage, length and load that is being put down the cable. So not every situation is alike.
 
Mcas4380 said:
Now keep in mind that i'm a newbie so i'm still trying to figure this out. but wouldn't this controller cost you half what you r looking at and save you on power supplies? http://www.j1sys.com/ecg-p12r/
I also may believe that there is more DC options that could drive the cost down.
Keep in mind i'm still trying to figure tis all out myselfSo if i'm wrong someone please jump in here.
Click to expand...

The way I see it, with twelve trees, even if I lowered the pixels to 300 per tree, that is 3600 pixels and I would probably need two p12r controllers @ $175 each, so $350 total (instead of $410 for higher count of the less expensive models I listed above). Power is power, I think. Regardless of how many controllers I use, I will still have a max of number of pixels x 0.3W and I thought that two x 100W power supplies would cost the same as one 200W power supply. Have to double check that, but that's what I think I remember.

I actually did another calculation using 300 pixels per tree and using one p12r to control six trees (two outputs per tree). The majority of the cost reduction was because of the lowering of pixel count.

-Louie
 
ɟɐsʇǝppʎ said:
One important factor that will determine how much power injection is required is how far away the lights are from the power supply. Thed amount of lights that can be run will vary depending on this because in many situations you could find that you have already lost over 1 volt when the lights are on. Using one colour may not show any difference and even 2 colours, but if going white then this could easily show with the end of the string becoming pinkish. So your initial volatge drop will be dertermined by the cable guage, length and load that is being put down the cable. So not every situation is alike.
Click to expand...

I think I understand. I had contemplated having a dedicated power supply at the base of every tree and might still do that... that way I would just have to run a data cable from the j1sys controller to the tree. If I go with 300 pixels, that is 90W, so maybe 120W power supply... distance from power supply to lights would be ~ 1 meter...

-Louie
 
Another thing to be aware of is that pixels tend to be a whole lot heavier than traditional led string. At a guesstimate I'd say that they are probably around 3 times the weight for a given number of leds. This is because there is more wiring, the wire is heavier, the leds are a lot bigger and there is a fair amount of epoxy that the led and the pcb is potted in.
 
AAH said:
Another thing to be aware of is that pixels tend to be a whole lot heavier than traditional led string. At a guesstimate I'd say that they are probably around 3 times the weight for a given number of leds. This is because there is more wiring, the wire is heavier, the leds are a lot bigger and there is a fair amount of epoxy that the led and the pcb is potted in.
Click to expand...
I guess that makes sense. The existing trees that I've used for years are loaded with upwards of 2400 incandescent mini lights in a six foot tree (600 each red, green & white, but then green is double wrapped because the original greens were horrible looking, but they were buried under the red and white and I didn't feel like unwinding the old lights when I added new lights). The branches definitely struggle with that many lights, but I'm hoping 300 of the pixels will be more reasonable.

-Louie
 
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