Dumb RGB Leds

[HVACR]

I have a dumb question. I am looking at some RGB lights from Ray Wu. The data says that the leds are .24W each so 100 leds are 24Watts. The LOR controller CMB24D says 4 amps per channel. This will control 8 different sets of lights with 3 channels per set. RED-Green-Blue. So does that mean 12 amps per light set? Working the math: 12ampsX 12Volts=144Watts / .24Watts per pixel= 600 pixels max per light set? Is this the right way to calculate the number of pixels? Thanks HVACR.

[jerry72]

I looked at the Specs, you can have up 30 amps per side of the board, i would not push more then 6.5 amps per output, so i would not put more then 110 nodes per set. What ya have to remember is that each node, at full white is right around .057 amps max, my testing for 50 nodes with a couple different strings was .052 to .057 per node at full white. 

Edited January 4, 2016 by jerry72

[jerry72]

I should ad, that if you never pan to run full white, then you could run 140 nodes per string, but i would just stick with 110 so you can use white as well.

[HVACR]

Well I didn't get an answer here that I liked to I called LOR tech support. My thought was 4 amps per channel X 24 Channels = 96 amps. That makes my math wrong. Mike said 4 amps per RGB channel. That works out to 32 amps. Why have 60 amps of possible input if you could only get 32 amps out. He said I had a point. We both must be wrong. He has kicked it up the food chain to engineering. I will post the answer  when I get it. That's pretty good when I can stump tech support.

HVACR 

[k6ccc]

I have a dumb question. I am looking at some RGB lights from Ray Wu. The data says that the leds are .24W each so 100 leds are 24Watts. The LOR controller CMB24D says 4 amps per channel. This will control 8 different sets of lights with 3 channels per set. RED-Green-Blue. So does that mean 12 amps per light set? Working the math: 12ampsX 12Volts=144Watts / .24Watts per pixel= 600 pixels max per light set? Is this the right way to calculate the number of pixels? Thanks HVACR.

 

No.

Each of the 24 channels can handle 4 amps max. with no heat sinks or 8 amps with heat sinks.  The card could not care less if that channel is being used for one third of a RGB set or a single color.  There is also a 30 amp limit for each half of the board (channels 1 - 12 and channels 13 - 24).  I am a little more conservative than Jerry72 in that I use 60mA per LED for full white when calculating load (besides, the math is easier with the even number).  That will be just under 20mA for each color (and therefore, each channel) per RGB LED.  So, based on the 4 amp limit per channel, you could use 200 RGB LEDs on a channel set (200 x .020 = 4 Amps per channel).  That would put the three channels for that RGB set at just under 4 Amps each.  Now, you can't run all the channels full white while fully loaded at the same time because you would exceed the 30 Amp load per side of the board by quite a bit.

 

Your 600 LED calculation was based on allowing each color to draw 12 amps, not 12 amps for the three color channels combined.

Edited January 6, 2016 by k6ccc

[jerry72]

No.

Each of the 24 channels can handle 4 amps max. with no heat sinks or 8 amps with heat sinks.  The card could not care less if that channel is being used for one third of a RGB set or a single color.  There is also a 30 amp limit for each half of the board (channels 1 - 12 and channels 13 - 24).  I am a little more conservative than Jerry72 in that I use 60mA per LED for full white when calculating load (besides, the math is easier with the even number).  That will be just under 20mA for each color (and therefore, each channel) per RGB LED.  So, based on the 4 amp limit per channel, you could use 200 RGB LEDs on a channel set (200 x .020 = 4 Amps per channel).  That would put the three channels for that RGB set at just under 4 Amps each.  Now, you can't run all the channels full white while fully loaded at the same time because you would exceed the 30 Amp load per side of the board by quite a bit.

 

Your 600 LED calculation was based on allowing each color to draw 12 amps, not 12 amps for the three color channels combined.

Ya know, i just went back and looked at the specs for the nodes, it does say 60ma, i have just always went off the .057. But yer right, always leave wiggle room. I plan to run no more then 100 nodes per output. At all white, that will put me right at 24 amps per side. that leaves me with an 8 amp cushion.

 

Good call Jim

Edited January 6, 2016 by jerry72

[HVACR]

This is the response from LOR:

 

"A Light-O-Rama help desk staff member has replied to your request, #856285 with the following response: 

Hello, 

The CMB24 has 24 ports. Each port can handle 4A. However that would add up to 96A if you ran all of the ports at the full 4A and the result would be that the fuses interrupt. Each side of the card has 12 channels and each side of the card can handle 30A total for a total of 60A for the card." 
 

Mike said "the power ratting for a LED is for White. All 3 on at full power to get white color. The leds are .24 watts each. That is .08 watts per color input (Red, Blue, Green)." The controller is capable of 12 amps per RGB channel. This would be a max of 600 leds per channel. However you would be unable to run more than 30 amps per bank of channels. No more than 1500 leds on at any one time per bank or it will blow the safety fuse.

 

Thanks for the information about adding a heatsink to the board. I just have one controller that will have 2 channels with around 250 leds. I will just need to remember to put one on each bank of channels.

 

HVACR

[jerry72]

This is the response from LOR:

 

"A Light-O-Rama help desk staff member has replied to your request, #856285 with the following response: 

Hello, 

The CMB24 has 24 ports. Each port can handle 4A. However that would add up to 96A if you ran all of the ports at the full 4A and the result would be that the fuses interrupt. Each side of the card has 12 channels and each side of the card can handle 30A total for a total of 60A for the card." 

 

Mike said "the power ratting for a LED is for White. All 3 on at full power to get white color. The leds are .24 watts each. That is .08 watts per color input (Red, Blue, Green)." The controller is capable of 12 amps per RGB channel. This would be a max of 600 leds per channel. However you would be unable to run more than 30 amps per bank of channels. No more than 1500 leds on at any one time per bank or it will blow the safety fuse.

 

Thanks for the information about adding a heatsink to the board. I just have one controller that will have 2 channels with around 250 leds. I will just need to remember to put one on each bank of channels.

 

HVACR

Remember, when they say 600 LED's per channel that comes out to 200 pixels. There are 3 led's per pixel.