Meanwell LDD driver: for those who want to dim to 0 using Arduino

back with a heat report on the new LDD drivers. I placed all 8 drivers on a 8up board but only ran 4 @ 36v 1.4mah in side a Radio Shack large plastic project box 8x6" bought from local store. I cut 2 1/2 inch openings out of the box end to pass the wires threw ran all 4 drivers powering 4 50W leds for 30 min with no fan and no air openings and temp went up to 95f might of went a little higher but at that point I didn't want to over heat the drivers. my room here is at 77f ambient temp. So if I would of had all 8 running the box would of over heated and probably shortened the life of the drivers. Soon as I opened the box heat drooped to normal room temp of 80f in less than 5 minutes. Next used a small computer fan 12v @0.14mah blowing in to the same box with lid half open and rested the fan on the box edge and lid blowing down on the board, with no real heat change stayed under 80f for 30 min. If there is anything else that anyone wants test with these I would be happy to do it if I can. Between now and middle next week, after that I am taking the test rig apart to put it over my tank
 
back with a heat report on the new LDD drivers. I placed all 8 drivers on a 8up board but only ran 4 @ 36v 1.4mah in side a Radio Shack large plastic project box 8x6" bought from local store. I cut 2 1/2 inch openings out of the box end to pass the wires threw ran all 4 drivers powering 4 50W leds for 30 min with no fan and no air openings and temp went up to 95f might of went a little higher but at that point I didn't want to over heat the drivers. my room here is at 77f ambient temp. So if I would of had all 8 running the box would of over heated and probably shortened the life of the drivers. Soon as I opened the box heat drooped to normal room temp of 80f in less than 5 minutes. Next used a small computer fan 12v @0.14mah blowing in to the same box with lid half open and rested the fan on the box edge and lid blowing down on the board, with no real heat change stayed under 80f for 30 min. If there is anything else that anyone wants test with these I would be happy to do it if I can. Between now and middle next week, after that I am taking the test rig apart to put it over my tank


Rott-

From the Allegro A6211 spec sheet- Maximum Junction Temperature TJ(max)= 150 ºC

The chip carries it's own Thermal Protection circuitry, so it will shut itself down if temps are allowed to exceed130 ºC . I've yet to kill one myself, so I'm pretty sure the drivers will operate reliably (in a properly ventilated enclosure) for years to come. Now, if I could just get my hands on more chips! They're on back order until 3/15/2014. Grrrrrrrrrrrrrr! :headwalls:
 
I am adding 10 3w RB leds to my reef tank do I need to start them on low then turn them up over the next week or any thing to give my coral a chance to get use to the new lights?

I know I would with daylight leds but not sure about all Rb's
 
that tank dosen't seem over bright. I just wanted to add some xtra deep blue actinic for the corals. Not looking to change color of the tank look
 
I think that with only 10 LEDs and 800+ watts of halides you won't see much of an effect - fluorescence is drowned out very quickly, which is why most you see all the hyped up corals for sale are photographed under only royal blue LEDs for as much fluorescence to be seen as possible.
 
I am not looking to make the corals fluorescence or (pop) in color. I just wanted to add extra blue for health of corals to make sure they get enough blue and I am not sure that the MH are providing
 
While the Hamilton bulbs are not overly blue, they provide plenty of PAR, especially in 400w, so as far as growth you're covered.
 
Ok I'm feeling really lazy now someone have this answer on the fly? How many Cree XTE bulbs can I run off one LDD driver with a 48V power source? I think the LDD saps a couple volts, but was unsure how much.

Also, how thin can I go on the wire for the PWM control? pull a couple strands out of some cat5 will be ok? Any length restrictions? I'm looking to keep my power supply as far away from the tank as possible (well outside of the "humid zone" that will be enclosed) and I'm debating having the LDD drivers on the heatsink, or next to the PSU... I guess next to the PSU would be easiest though since I only need to run PWM to the controller and PSU.
 
The LDD output around 45v with 48v input, and as you get closer to 56v input that widens to 4v.

PWM wire can be almost anything. You're transmitting a minuscule amount of power. I'd still keep the runs as short as possible, though.

For power supply, if you've got the extra you can spend on it, the Meanwell HLG series can run in constant voltage mode and are IP65-67.
 
Hmm, just checked the data sheet for the XTE bulbs says typical forward voltage is 2.85V, that's a lot lower than I thought thought it was closer to 3.3V.

I looked at the HLG series, especially after my first meanwell sucked in too much humid air and corroded out. But it's a hard sell for me when a similar power HLG will cost 2-3 times more, just seems easier to keep the PSU further away and run a little bit longer wires.

edit: also seems to be the availability of a 320w version in 48volt configuration is about the same as the LDD drivers when people figured out how great they were.
 
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Hmm, just checked the data sheet for the XTE bulbs says typical forward voltage is 2.85V, that's a lot lower than I thought thought it was closer to 3.3V.

I looked at the HLG series, especially after my first meanwell sucked in too much humid air and corroded out. But it's a hard sell for me when a similar power HLG will cost 2-3 times more, just seems easier to keep the PSU further away and run a little bit longer wires.

edit: also seems to be the availability of a 320w version in 48volt configuration is about the same as the LDD drivers when people figured out how great they were.

Forward voltage is a product of forward current - current rises, so does the voltage. I've measured a few myself, and you'd be hard pressed to find an XT-E that hits 2.85v with more than ~350mA.

The HLG is pretty available - Jameco is 5 days ARO, onlinecomponents has a few in stock with more on the way. The HLG has been around for a long while, so there shouldn't be any stock issues with them. Are you set on needing the 320w version? There are also 240w, 185w, 150w, 120w, 100w, 80w, 60w, and 40w versions.
 
Set on using the 320w version? No, that's just the output of my current Meanwell SP-320 so used that as a comparative source when pricing.

My original fixture I made had 4 clusters of 3 + 3 of NW/RB XTE plus a mix of 12 XPG/XTE Blue/RB and 12 Violet, 4 channels total, running the clusters at 1000ma, and the other 24 at 700mA, it pulls somewhere on the order of 140 watts, so I figure 2 could be run off one 320watt power supply and that gives me a little headroom.

Now the reason I went for the 320watt PSU is because that seemed to be the most economical, price per watt, a larger PSU cost significantly more, and multiple smaller ones cost more as well. Just looking at the HLG at Jameco ~68.95 for a 120W supply, 70.95 for a 150W supply, $84.95 for a 240W, $122.95 for the 320W . So seems that the 240W is the most economical followed closely by the 320W version. Being as I need at least 140W, the 240W actually doesn't become very friendly because I'm not taking advantage of the power I could have available. So once again the 320W version seems the way to go.

However, I have been toying with reducing the LEDs on my fixtures by 25% so I have 3 clusters and then 9 & 9 of the others, simply because it might be a bit too might light crammed on a 20" heatsink, and also go from 4 channels to 3 channels, violet, a nw/rb channel and a rb/blue channel (which is why I asked about how many I could throw onto one LDD), so that reduced my power need to about 105W. Which I can run 3 of a 320 or 2 off a 240. I'm not really keen on doing one PSU per fixture though, just too many wires to worry about.
 
just a question, which might have been answered already. I have a set up using LDD's and Jarduino, which works fine. Is there any way I add a further dimming control using a potentiometer and transistors to dim the leds. The reason for this is to easily lower the intensity of light during acclimatisation instead of fiddling with the Jarduino which is set up as I want it?
 
just a question, which might have been answered already. I have a set up using LDD's and Jarduino, which works fine. Is there any way I add a further dimming control using a potentiometer and transistors to dim the leds. The reason for this is to easily lower the intensity of light during acclimatisation instead of fiddling with the Jarduino which is set up as I want it?

Send me a PM. I've got what you're looking for. It's a 4 channel manual dimming controller that's similar to the Apex convertor posted earlier in this thread. It uses on board potentiometers to dial in your desired lighting levels. Here's a photo-

8upLDD-H_with_Dual_SCW003_zps2fda3cf2.jpg
 
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