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Powering LED Light strings


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Well I have purchased a number of mini trees that come with LED lights.  I would like to use a CMB24 RGB controller for this.   I am not a complete novice to basic electric, ohms law and such, but I am novice when it comes to driving LED light strings.   The driver for the light strings I have are 30v .08 amp output.  I was planning on getting constant voltage or current limiting power supply as I have read it is not the voltage that is important with LED's but the current flow.   I have 24 of these trees, but one driver powers 3 connected in parallel.


I am planning on the CMB24 since it allows 24 channels and will allow me to go into RGB products in the future.  


Please advise.


Thanks for all your help and I look forward to working with the group this year.



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The mini trees are run from a driver that is 110V ac input and 30V dc at .08A   output. My plan was not to use the drivers that came with the trees but purchase a supply.  Note that one driver powers 3 tress at once. But I want to control the trees, one on a channel.  So I have 27 trees but only 9 drivers.  


I did a volt measurement on the trees and they are at 30V.

As of today I have not done a current measurement. 

I thought the  CMB24 took its voltage from one of the 12 channel banks but as long the voltage was greater or equal to 12V that would be fine.

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I believe the cmb board can handle 30volts dc imput. are your trees rgbS or just one color led's their are 24 channels on the board but its set up for rgb 1+ 3- channels

Edited by Dennis Laff
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I dont have one of these boards, but I was to think that this is a 24 channel versus the older boards only being 16 channels. Nothing special about these boards just can control 8 dumb RGB devices as opposed to only 5 dumb RGB devices with the older board.Not sure about the max voltage. I think if it is anything like the older board. Minimum voltage is like 9 volts and 60 volts is max. The one of two is powered by a 49 volt supply and works just fine.


Now srobin, You speak of a driver. Just what is this driver? Does it make the LEDs change color? What color are the LEDs if they are just one color? Lots of the common LEDs draw .02 amps. Makes me wonder if each of these trees only have 10 LED per tree.


Ok, so each of these trees are in parallel. and each tree is a single color. Then each tree would go to a separate channel and you would need to come up with a 30 volt power supply. Current output of the supply would be .03 amps times the number of trees.

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Sorry, As you can tell a numbee here. I should have told  you this but these are standard dumb led light strings. There is 60 bulbs per tree. The driver just powers the 3 strings nothing more.

Note the strings are connected to the driver via a special cable and they are wired in parallel

Time to purchase a 30v power supply.


The board does not have to be used for RGB but I am using it because I may wish to go to RGB next year.


This was my first year and only used 32 channels, I plan to go to 200 channels for 2014.


Thanks for all your help, just wanted clarification.

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No last year was your first year. For this is already 2014 and I presume it is this year you will be going to 200 channels.


Your math does not add up. You say that there are 60 bulbs per tree. That would leave you with .5 volt per LED. Does not work out right. Red, yellow and orange are between 2 to 2.2 volts each. Blue, Green, White and a few other colors are all in the 3.3 to 3.6 volt range. Depending on the color of the tree or mixture. Each tree is a dual or tri parallel circuit of LEDs. And each circuit is usually like 20 mA each. So a single tree would draw between 40 and 60mA. Times 3 trees will bring you up to .12A to .18A combined. So, the math is off somewhere.

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