Explain Mean Well LDD's like i'm five...
- Thread starter Pearson
- Start date
Thanks for the feedback, but it looks like you CAN run LDD drivers in parallel if you isolate each driver with a diode. See post 12 and 13 below.
http://www.nano-reef.com/topic/330355-ldd-driving-more-then-1000ma/
http://www.nano-reef.com/topic/330355-ldd-driving-more-then-1000ma/
Actually the ELN is both a constant current and constant voltage driver depending on how you set the svr1 and svr2 pots internally. So it can power LDD drivers. (I've not seen it done yet or tried it with an ELN but I'm using a 4 amp PLN this way with no problems) Next time I'm tinkering in the basement I'll test this as the question seems to come up alot, but by the specs it should work just fine.
Answer to question number 2 is still a NO. at least until I or someone runs them like that for a while. O2 and others tested similar configurations in the giant LDD driver thread and had some issues with one driver heating up or all the return current going thru one LDD as I recall it was abbandoned as not a good idea even though it does seem to work, I've not yet seen long term use this way.
FWIW they now have 1.5 amp LDD-L coming out that fits the standard LDD-H pcb with a minor tweak and use of mounting sockets.
Great info! Do you know if anyone tried isolating the LDD drivers with diodes when running them in parallel, as discussed in the thread I linked above?
I tried it way back when the LDD craze was just starting to pickup steam. I used diodes just like the arrangement shown in the link that you posted. I found that the output current could be effectively doubled, but the load was not evenly split between the two LDD's. It appeared that the current was been sourced from only one LDD in the pair. I discontinued testing for fear of damaging my LDD's, as the LDD that was carrying all of the current ran considerably hotter than normal, and would probably fail earlier than it's projected life span.
No I didn't try using any resistors. An even weirder observation that I made was this- It seemed that whenever power was first applied, whichever LDD switched "On" first, that LDD carried the current load. The second LDD appeared to be just sitting there doing nothing. I even went so far as cutting the power momentarily to the LDD that appeared to be doing all the work, in an attempt to jump start the second "idling" LDD. The "idling" LDD would then power "on" and produce it's rated current. Just as soon as power was reapplied to the first LDD, the second LDD would then double it's current output and carry all of the load. I now wonder what would happen if the input power could be toggled on & off between the two LDD's. Maybe if they were both powered by a pulsed DC signal 180 degrees out of phase to each other, they'd still be able to double their output current since they're both being powered using a 50% duty cycle? The net effect should be double the current but even sharing of the current/heat load between the two LDD's . Maybe I should experiment again?
Interesting.....
So on a side note O2 this just dawned on me but that driver schematic from the Sure Electronics driver I posed early in the LDD thread basically runs the same way as an LDD I think, and sources current directly from the PSU into the LED array with a diode in series, possibly this could be done with heavier gauge wire bypassing the LDDs to let the LDDs share the return current not the source current???????
I may not be remembering all the tests you did correctly, If it was return current only going to one LDD then this wouldn't work, and I've never measured the Sure divers to see what they are doing exactly.
I also know that the Sure driver parallel design maxes out at 1.5 amps from the manufacturer and the chip just happens to also be rated for 1.5 amps. Also I doubt the PCB traces could handle any more than 1.5 amps.
We don't know what the LDD components are rated at until someone cuts one open and finds the part numbers some how......can you even do that with something that's been potted?
oreo57
Well-known member
AFAICT no...
LDD's have very little overhead. Your LED's will "consume" ROUGHLY at most
183W.. (3x 61)
You would have to do the calculations for more accuracy
W=VXA for each channel..
example 12 LED's @1000mA V(f)= 3.2V
=38.4W for one channel
The PWM dimming circuit requires little current..and the added current of 5 meanwells on that circuit is withing the Coralux range..
No, the PSU can be as large as you want, as long as it can supply at least 20% more watts than your LED array will be drawing at maximum (100% power) calculated per above example. (also assuming your LEDs can handle the Current the LDDs are giving them, you didn't say what you were running)
The PSU voltage must also be larger than the longest LED string plus 3 volts for the LED so example for that: 12 LEDs at 3.5v (assuming cheap ebay LEDs) plus 3v for LDD equals 45volts so as long as the PSU is 45 volts or higher (up to 54 volts for the LDD-H) then you are good.
That will depend on the voltage of the power supply and the voltage drop of the LED's. Are you using the LDD-H or LDD-L drivers?
Don't know never tried it as they aren't intended to do that.
Any of the CC+CV (constant current plus constant voltage) LED drivers can be used. These include the ELN, CLG, HLG, and other models from Meanwell. Use the models that are adjustable but not meant for external dimming control.
Kaiserman1967
New member
Cree XT-E Meanwell LLD1000
Cree XT-E Meanwell LLD1000
I've been reading through the huge amount of information about DIYing a light setup. One question I have not seen answered is the size wire you should use to connect the LED (Cree XT-E Royal Blue and 6500K 5W) together, connection to the 5up board with LDD1000 (What I plan to use) and then to the PSU.
Does the wire only need to handle 1amp?
Would 24 AWG solid core be good enough or should I use 22 AWG or bigger?
I also wondered everyone's take on a good rule of thumb for the LED wattage for a tank. I know there are a ton of variables, but just looking for generalizations. I have a mix of fish, soft and stony corals and one pretty large BTA (Basketball size). Everyone is currently in a 55Gal, but I plan to move into a 150 Gal very soon. I would like to build an LED setup for the new tank.
Also, do you think using more than just the 2 colors is recommended such as UV, Warm white (3000K), Red or Green?
Cree XT-E Meanwell LLD1000
I've been reading through the huge amount of information about DIYing a light setup. One question I have not seen answered is the size wire you should use to connect the LED (Cree XT-E Royal Blue and 6500K 5W) together, connection to the 5up board with LDD1000 (What I plan to use) and then to the PSU.
Does the wire only need to handle 1amp?
Would 24 AWG solid core be good enough or should I use 22 AWG or bigger?
I also wondered everyone's take on a good rule of thumb for the LED wattage for a tank. I know there are a ton of variables, but just looking for generalizations. I have a mix of fish, soft and stony corals and one pretty large BTA (Basketball size). Everyone is currently in a 55Gal, but I plan to move into a 150 Gal very soon. I would like to build an LED setup for the new tank.
Also, do you think using more than just the 2 colors is recommended such as UV, Warm white (3000K), Red or Green?
I would always use 22AWG for up to 1A.
Can't really help with the other question as there are too many variables. I tend to look to an off the shelf solution as a base and then tinker with the design. But (for example) 50W of LED doesn't really tell you much. Even using exactly the same LED (so make, model and bin) running at 50W can give a level of light that varies by over 60% depending on how hard you drive them (by that i mean running 10 LEDs at 5W each or, to get the extreme example I qoute, 188 LEDs at 0.265W). And that is before you introduce the significantly higher variations you get with different make/model/bins! Of course, no one is ever going to run them quite that low! That was just to give an example
More colours is a good idea. How many and what balance is a different matter. Personally I'd go for a mix of RB, Blue, Cool White, Neutral/Warm white and then maybe one or two exotics, but I'd have a play to see what affect these had on the tank. Limes are often recommended, and then things like turquoise, cyan, etc.
Tim
Can't really help with the other question as there are too many variables. I tend to look to an off the shelf solution as a base and then tinker with the design. But (for example) 50W of LED doesn't really tell you much. Even using exactly the same LED (so make, model and bin) running at 50W can give a level of light that varies by over 60% depending on how hard you drive them (by that i mean running 10 LEDs at 5W each or, to get the extreme example I qoute, 188 LEDs at 0.265W). And that is before you introduce the significantly higher variations you get with different make/model/bins! Of course, no one is ever going to run them quite that low! That was just to give an example
More colours is a good idea. How many and what balance is a different matter. Personally I'd go for a mix of RB, Blue, Cool White, Neutral/Warm white and then maybe one or two exotics, but I'd have a play to see what affect these had on the tank. Limes are often recommended, and then things like turquoise, cyan, etc.
Tim
oreo57
Well-known member
"A" chart:
http://www.docthrock.com/Electrical_files/WireSizeChart.JPG
What is good enough for a plane is good enough for me..
Short runs between diodes is not as critical as long runs to ps ect..
Kaiserman1967
New member
I would always use 22AWG for up to 1A.
Can't really help with the other question as there are too many variables. I tend to look to an off the shelf solution as a base and then tinker with the design. But (for example) 50W of LED doesn't really tell you much. Even using exactly the same LED (so make, model and bin) running at 50W can give a level of light that varies by over 60% depending on how hard you drive them (by that i mean running 10 LEDs at 5W each or, to get the extreme example I qoute, 188 LEDs at 0.265W). And that is before you introduce the significantly higher variations you get with different make/model/bins! Of course, no one is ever going to run them quite that low! That was just to give an example
More colours is a good idea. How many and what balance is a different matter. Personally I'd go for a mix of RB, Blue, Cool White, Neutral/Warm white and then maybe one or two exotics, but I'd have a play to see what affect these had on the tank. Limes are often recommended, and then things like turquoise, cyan, etc.
Tim
Tim,
If I was running the 5W Cree XT-E at 1amp, doesn't that pretty much tell you it'll be pushing 3.2 to 3.6 Watts? As far as the cree bulbs go, I haven't really seen anyplace that specifies what bins they are out of. Even on the cree website, they don't mention anything about bins and quality. I'm sure bulbs that come from across the western pond will be less quality than say, rapidled, but do the cree bulbs really have that much difference in quality like other brands?
I really appreciate the advice! I wondered about running different colors, but then I'd need a driver for each color wouldn't I?
Right now im having a similar problem... i know the ELN/PLN drivers, but nothing about PSU and LDD. Here's what i got going on...
Looking at making just 2-3 "spot lights" for now to target 3 specific corals. Eventually in the future i plan to upgrade this as i can by adding more "spot lights" until the entire tank is lit with LED as i get more money. So, from what ive seen, LDD and PSU is the way to go... for the spot light im looking at right now. To make each one i plan on
2 cree CW XP-G2 (1500mah)
2 cree RB XT-E (1500mah)
1 semiLED UV (750 mah)
Each color on a separate driver and dismantle with POT
So, for 2 spot lights.
4 CW
4 RB
2 UV
1 LDD 700
2 LDD 1000
Power supply im looking at http://www.invertersupply.com/media/data/DV480.pdf
So, how do i wire this ans work it so that i dont burn the leds out until i get more of them to run full strings? And then... how do i run said strings?
Looking at making just 2-3 "spot lights" for now to target 3 specific corals. Eventually in the future i plan to upgrade this as i can by adding more "spot lights" until the entire tank is lit with LED as i get more money. So, from what ive seen, LDD and PSU is the way to go... for the spot light im looking at right now. To make each one i plan on
2 cree CW XP-G2 (1500mah)
2 cree RB XT-E (1500mah)
1 semiLED UV (750 mah)
Each color on a separate driver and dismantle with POT
So, for 2 spot lights.
4 CW
4 RB
2 UV
1 LDD 700
2 LDD 1000
Power supply im looking at http://www.invertersupply.com/media/data/DV480.pdf
So, how do i wire this ans work it so that i dont burn the leds out until i get more of them to run full strings? And then... how do i run said strings?
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