Nutcracker: Show current consumed in real time

[smeighan]

I was wondering how much current my future megatree would be consuming. I know when i gave the option to set a background color that there would be a jump in current draw. All picels having a color would increase current, but by how much.

So ..

I now loop through each frams and look at every pixel. I look to see the highest RGB value and change that to a 0-100%. This is the V in an HSV model. I then multiple the percentage by the current draw of a single pixel.

The wiki page, You are not allowed to view links. Register or Login,  says that the pixels draw 29ma. But
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says they draw 56-60 ma.

So until someone tells me differently i am assuming 60ma for a full on pixel.

Having done this math, i know how much each strand of the tree uses during each frame of the animation.

I then made an animated gif of the current draw. It is interesting to change parameters in the effect model and see how it effects the current draw for the whole tree.


_POST
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spiral_thickness   3
window_degrees   360
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end_color   #0464F5
frame_delay   22
direction   cw
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use_background   n
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submit   Submit Form to create your target model

submit   Submit Form to create your target model


produces this current graph



Now I will do the same effect , but turn on background color
_POST
username   f
user_target   AA
effect_class   spirals
effect_name   CURRENT2
number_spirals   4
number_rotations   2
spiral_thickness   3
window_degrees   360
start_color   #FF1C42
end_color   #0464F5
frame_delay   22
direction   cw
sparkles   0
use_background   Y
background_color   #29D107
submit   Submit Form to create your target model



and see the current change



Now i can plan on how many extra lines i need to run my tree. I think a 15amp socket wont do the trick.

[Steve Gase]

might be interesting to see the current draw for each channel considered...  50% of RED, 100% of BLUE, 0% of GREEN.

when I have time to get my hands dirty again, i'll try to measure these out.

[smeighan]

might be interesting to see the current draw for each channel considered...  50% of RED, 100% of BLUE, 0% of GREEN.

when I have time to get my hands dirty again, i'll try to measure these out.

Here i what i am doing

30% RED  100% GREEN  50% BLUE, I use 100% x 60ma. This is because the V in a HSV model is the highest rgb value/255

30% RED  20% GREEN 10% BLUE, i use 30% x 60ma

I assume 60ma draw means 100% RED 100% GREEN 100% BLUE.


I knew someone smarter than me would suggest a better formula. The hard part (coding, graphing, array walks) is finished. I can update the formula used in a few minutes.

I am going to guess , its is close enough for planning purposes.

feel free to make a suggestion for a more accurate process.

[sjb]

With not having any smart strings yet, I am trying to understand this. So sorry if this is a dumb question, but what does a 15 amp socket have to do with smart strings. Are they not powered by a 12 volt DC power supply from the hub??

Steve

[smeighan]

With not having any smart strings yet, I am trying to understand this. So sorry if this is a dumb question, but what does a 15 amp socket have to do with smart strings. Are they not powered by a 12 volt DC power supply from the hub??

Steve

I meant that the ac power i will plug the power supplies that will provide the current to the smart strings will require more than 1 15amp socket. I was being facetious.

Maybe someone , most everyone , smarter than me can figure out to get 1amp 12v Dc  to an led string, how much current will the power supply need to draw from the AC line? I think current power suppiles are 75% efficient. there is loss due the length of the line.

I would love to be able to relate AC current draw as it relates to my calculated DC current draw.

thanks

[caretaker]

With not having any smart strings yet, I am trying to understand this. So sorry if this is a dumb question, but what does a 15 amp socket have to do with smart strings. Are they not powered by a 12 volt DC power supply from the hub??

Steve

You are correct.  60amps at 12 volt DC is a lot different than 60 amp at 120 volts AC.  Sean if your mega tree draws between 58 and 60 amps then you will need just one 15 amp circuit for the power supply to your Smart String hub.

[smeighan]

With not having any smart strings yet, I am trying to understand this. So sorry if this is a dumb question, but what does a 15 amp socket have to do with smart strings. Are they not powered by a 12 volt DC power supply from the hub??

Steve

You are correct.  60amps at 12 volt DC is a lot different than 60 amp at 120 volts AC.  Sean if your mega tree draws between 58 and 60 amps then you will need just one 15 amp circuit for the power supply to your Smart String hub.

this is why i leave these things to the electrical engineers around here.

So i found this on the web:

Here are the recommendations for the minimum combined 12V rail amperages (and their relative PSU wattage rating) for various size computer systems:

Small Form Factor - 15A (250W)
Mini-Tower - 25A (300-350W)
Mid-Tower - 35A (400-500W)
Full Tower - 40A (600-650W)
Dual Video Card (SLI) - 60A (850W+)


So a full tower would draw around 5amps (600W/120V) from the AC line and produce 40amps of 12V power?

I should clarify my wbe page to say current drawn on 12V Dc line.

thanks

[Steve Gase]

With not having any smart strings yet, I am trying to understand this. So sorry if this is a dumb question, but what does a 15 amp socket have to do with smart strings. Are they not powered by a 12 volt DC power supply from the hub??

Steve

You are correct.  60amps at 12 volt DC is a lot different than 60 amp at 120 volts AC.  Sean if your mega tree draws between 58 and 60 amps then you will need just one 15 amp circuit for the power supply to your Smart String hub.

60 power-supply-amps x 12v = 720 watts.   
720 watts / 110v = 6.54 amps out of your house.

you could put 2 power supplies on that circuit.

[smeighan]

With not having any smart strings yet, I am trying to understand this. So sorry if this is a dumb question, but what does a 15 amp socket have to do with smart strings. Are they not powered by a 12 volt DC power supply from the hub??

Steve

You are correct.  60amps at 12 volt DC is a lot different than 60 amp at 120 volts AC.  Sean if your mega tree draws between 58 and 60 amps then you will need just one 15 amp circuit for the power supply to your Smart String hub.

60 power-supply-amps x 12v = 720 watts.   
720 watts / 110v = 6.54 amps out of your house.

you could put 2 power supplies on that circuit.

so steve, caretaker;

Would this be a better label for the graph? "Total 12V DC Current for frame"

[Steve Gase]

Here are the recommendations for the minimum combined 12V rail amperages (and their relative PSU wattage rating) for various size computer systems:

Small Form Factor - 15A (250W)
Mini-Tower - 25A (300-350W)
Mid-Tower - 35A (400-500W)
Full Tower - 40A (600-650W)
Dual Video Card (SLI) - 60A (850W+)


So a full tower would draw around 5amps (600W/120V) from the AC line and produce 40amps of 12V power?

I should clarify my wbe page to say current drawn on 12V Dc line.

thanks

Even though these power supplies are built for a PC, I wouldn't bother looking at those tiers.

Figure out what you will need for your strings...  add the amount needed for each SSC's overhead... add the amount for your hub.

that will give you a number of 12v watts that you will need.
build in a safety margin...  selecting a power supply that uses no more than 80% of the rated 12v power is good.

that gives you the 12v watts you should buy...  divide by 12 and you get the 12v amps you need in the power supply rating.

now look for a power supply that has single rail power.  look at the specs for the 12v power.

sounds like a lot, but it makes sense eventually.


N-strings X ( ssc-amps + ( pixel-count  X (watts-per-pixel / 12-volts ))) = 12v-amps-needed
(12v-amps / 80%) = 12v-amps-to-buy

lets try maxing it out:

16-strings X ( .06-amps + (128-pixels X (.356-watts / 12-volts ))) = 63.23-amps
(63.25 / .80 ) = 79-amps 

this means your power supply should have a rating of  (79-amps X 12v = 948 watts)

there is a little bit of 5v power on that supply, but a 1000watt supply should do you.

[smeighan]

Steve you have the biggest tree i have seen in Nutcracker, 48 strings x 85 pixels.

I ran your tree with a solid background color.

_POST
username   Steve Gase
user_target   SGMEG48
effect_class   spirals
effect_name   SEAN_TEST2
number_spirals   4
number_rotations   2
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window_degrees   360
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end_color   #5EF4FF
frame_delay   22
direction   cw
sparkles   0
use_background   Y
background_color   #09FF00
submit   Submit Form to create your target model





So does that mean this animation on your tree would use 2928 watts (12V x 244 amps)?

[Steve Gase]

here is the problem with labelling and the direction you are taking.
what i see you doing is very specific to the 12v smart pixels.
there are plastic rectangles, metal squares, flex ribbons, rigid strips...

if you go outside of DLA you'll have different max pixels, 5v, and power draws.

i like having this custom to my own selections (DLA, 12v, smart pixels, SSC) but if you are trying to be broad to other forums and technologies i think you'll want to build in more flexibility

maybe (yet another) feature of your site is a definition of the controller type (and power) and the pixel type (and power) that each user specifies -- you can default to the DLA sweet spot.

[smeighan]

i was thinking of prompting for the current draw of a pixel when the user is defining his target model

Number of Strings?
Number of Pixels per string?
Current draw of a pixel? 60ma

[Steve Gase]

Last year I had 40 strings of 85 pixels.  A hub can only have 16 strings... and in my case I had 3 hubs with 14 strings, 14 strings, and 12 strings.

This year I plan to have 3 hubs -- each with 16 strings.

another factor to consider for people trying to lay it all out.   a hub can only provide 4096 channels... with 3-color RGB that is 4096/3 or 1365 RGB channels.  with me so far?  if you had 128 pixel strings, that is only 10 strings per hub because you'd exceed the accessible channels (unless you used string mode LOL).

if you wanted to wanted to use all 16 strings, then 1365/16 = 85 pixels per string.  <<< that is why i have 85.

HOW MUCH POWER? 

roughly (and forgetting the 80% rule)...

48 strings x 85 pixels x .356 watts-per-pixel = 1452 watts or 13.2 110v amps or 121 12v amps.

I will break MY CONFIG into 3 hubs, and take into account the 80% rule.

16 x ( .06 + (85 pixels x .029a)) / .80 =  50 12v amps or 606 watts.

[Steve Gase]

i was thinking of prompting for the current draw of a pixel when the user is defining his target model

Number of Strings?
Number of Pixels per string?
Current draw of a pixel? 60ma

Instead of amps, how about watts?

if you ask for amps you should also ask for voltage.