DIY LEDs - The write-up
- Thread starter JohnL
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jkopp36
New member
Well, rysher's suggestion to call Mean Well was a great one as the issue is solved - at least the reason for it.
The 50% max dimming mentioned before in this thread and others is the cause. As discussed previously, the datasheet for the HLG's was changed. This is because the drivers themselves were changed. For the 240's, it was around July 2011. I happen to have received earlier versions where the only dimming is with a resistor and is not linear. If you look at an old datasheet you'll know what I mean. Long story short - my 48v 240 is 100% with an open dimming circuit, 75% with a 620 ohm resistor or 50% with a 68 ohm resistor. The 54v version uses 820 ohm and 150 ohm resistors for 75% and 50% respectively.
TBH, this sorta sucks. I was really wanting to take advantage of the 1vdc-10vdc dimming. Not sure what I'm going to do at this point but I'm thinking with just using the 3 ELN's I already have instead. If anyone is interested in a great deal on the restricted dimming 240's just let me know.
The tech mentioned that to be completely sure you'll want to get a unit made Aug 2011 or later.
At least it wasn't my build. I was starting to think I was crazy!
The 50% max dimming mentioned before in this thread and others is the cause. As discussed previously, the datasheet for the HLG's was changed. This is because the drivers themselves were changed. For the 240's, it was around July 2011. I happen to have received earlier versions where the only dimming is with a resistor and is not linear. If you look at an old datasheet you'll know what I mean. Long story short - my 48v 240 is 100% with an open dimming circuit, 75% with a 620 ohm resistor or 50% with a 68 ohm resistor. The 54v version uses 820 ohm and 150 ohm resistors for 75% and 50% respectively.
TBH, this sorta sucks. I was really wanting to take advantage of the 1vdc-10vdc dimming. Not sure what I'm going to do at this point but I'm thinking with just using the 3 ELN's I already have instead. If anyone is interested in a great deal on the restricted dimming 240's just let me know.
The tech mentioned that to be completely sure you'll want to get a unit made Aug 2011 or later.
At least it wasn't my build. I was starting to think I was crazy!
brassmonkyballs
BMB
Stupid question but is there any chance whoever you bought them from would take them back? I would at least ask....worse thing is they say no. They're not exactly used.
jkopp36
New member
Already checked. Had to check of a box acknowledging no returns whatsoever. They are sticking to their policy. In their defense, the datasheet shown with the drivers on their website is the old one and I never thought to look at it.
TheFishMan65
New member
Sorry to hear about the version. I almost asked that earlier - I guess I should have.
Ask meanwell if they can send you a sample - after all you already bought 2.
Ask meanwell if they can send you a sample - after all you already bought 2.
TheFishMan65
New member
The common opinion is 2:1 royal blue to white. I went with CW and RB originally and think I will be changing 1/2 out the neutrals. Some folks think all neutrals. It is all your preference go look at some fixture where you know what kind of LEDs are in it.
TheFishMan65
New member
True, but consider this. You maybe running you white really low and the blues really high to get the color you want. But this means the blues will be running hotter and not as efficient as if you used a 2:1 ratio. You will also be able to produce more light and keep the color the same.
Just some thought, but you are correct.
Just some thought, but you are correct.
brassmonkyballs
BMB
And I might add that going 2-1 saves $ up front since the RBs are alot less cost than CW. Aside from that the CW are so so bright you really don't need that many of them as they easily over power the RBs
der_wille_zur_macht
Team RC
This is how I approach the problem:
1) decide which models/bins of LEDs you want.
2) determine how hard you want to push each one, i.e. what percentage of its max current you will run, which of course determines efficiency and output.
3) now that you know the output per LED for each color, pick the mix ratios to get the overall color you want. Then pick the total count to get the overall intensity you want.
This may seem either trivial or too complicated, but my point is this: you should be making decisions about color mix with efficiency and overall intensity in mind. When you use dimming to solve major color issues, you are drastically impacting efficiency and overall intensity.
1) decide which models/bins of LEDs you want.
2) determine how hard you want to push each one, i.e. what percentage of its max current you will run, which of course determines efficiency and output.
3) now that you know the output per LED for each color, pick the mix ratios to get the overall color you want. Then pick the total count to get the overall intensity you want.
This may seem either trivial or too complicated, but my point is this: you should be making decisions about color mix with efficiency and overall intensity in mind. When you use dimming to solve major color issues, you are drastically impacting efficiency and overall intensity.
jinks
New member
The tank im putting them on is not very large. I was going to use 24 (12 and 12). If i switch to 2:1 that puts me at 8 and 16 and making me need a second driver for the blues. I guess it wouldn't really hurt to go to 7 and 14. The tank is only 20"x18" so i think I'll be okay with anywhere from 20-24. If the cool whites are that overpowering your right i don't want to have to dial them down incredibly low.
der_wille_zur_macht
Team RC
Or have one driver that is all royal blue and one that is half royal blue and half white. The pseudo-white driver will still pretty much look white and you still get plenty of color blending capability. Or switch to a driver that is happy with 6 LEDs.
brassmonkyballs
BMB
+1 on running 1 driver with blue and whites and the other all blue
Widmer,
May I ask how you wired up your 48 LEDS on 3 ELN-60-48?
I guess two drivers with each a serie of 12 RB at 1000 mA, and the whites in parallel strings driven at app 700 mA?
Just wan't to know cause I'm wandering if that gives a good color mix, which I could use myself with my planned fixture...
rogermccray
Active member
Is there a good example of a DIY LED for a 30" deep tank? I am trying to figure out the lighting for my new tank and can't seem to find a set up that is specific to that depth.
I have an Oceanic 215 Gallon Bowfront, I know that light it will be a bit tricky but I think i can compensate for the bowfront easier with a DIY LED Kit instead of a fixture. Any help would be appreciated.
I have an Oceanic 215 Gallon Bowfront, I know that light it will be a bit tricky but I think i can compensate for the bowfront easier with a DIY LED Kit instead of a fixture. Any help would be appreciated.
TheFishMan65
New member
jinks check the data sheet to see how current affect lights, but I don't think you will loose much of your whites. Most folks tend to run everything closer to 750ma (at least IMO from what I have read).
TheFishMan65
New member
roger, I would recommend using tighter optics (maybe 40 degree) which may also require the LEDs being mounted higher.
I hope this helps.
I hope this helps.
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