DIY LEDs - The write-up

[ReefEnabler]

Someone should turn you into the SPCP!

I would not expect that to work. The pot is too much resistance even in it's high state. That is why the 10V not 12V too.

I'd suggest you buy a computer fan speed controller. Some are PWM gizmos that also don't dump a ton of heat. They also tend to be open for cooling unlike regular pots.

SPCP??

I guess I am just confused as to why the pot is dropping my voltage so much. I am using 2 more of the same pot on my 10v power supply to dim the meanwell signal, and the range there is the same as the supply voltage, 0-10.2v

Is it normal for one pot to have such a difference in resistance? Does this sound more like a cold solder joint perhaps?

I am using the same method to control the speed of the fans that cool my T5s, but they are only 80mm fans so the lower start voltage of them must be more forgiving. I will look into getting PWM fan controller, thanks!

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One more question for you Kcress or anybody else:

Is there any harm in having power to the 0-10v dimming circuit on the 60-48d meanwells, while there is no AC power? So leaving the 10v signal always on and only hooking the AC supply to timers.

 

[D5HP]

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One more question for you Kcress or anybody else:

Is there any harm in having power to the 0-10v dimming circuit on the 60-48d meanwells, while there is no AC power? So leaving the 10v signal always on and only hooking the AC supply to timers.

No issue at all.

In fact...I've been doing that for more than a year on my ELNs.

Meanwells are amazing little drivers!

 

[kcress]

SPCP??

Society for Prevention of Cruelty to Pots.


You would need to use a much lower value of pot. Like a 500ohms or a 100 ohm pot. Now think about that..

100 ohms across 12 volts all the time. Power = 12x12/100
P= 1.4watts. Most pots freak at about 250mW. This would put you into rheostat land.

I suggest you jut get a wallwart that's a 9V one and run with that, skipping pots and rheostats entirely.

 

[D5HP]

156 total 1W LEDs and optics -- about $180 after shipping

6 total ELN-30-48D drivers -- $150 after shipping (gotta find them in stock though)

These heatsinks would be about $60 after shipping.

I got four of the six fans from work today. I just need two more 80mm ones.

Here's my mock layout. Now each red strip represents a 1" wide heatsink in varying lengths. The ones towards the front of the tank will be tilted towards the rock structures in my tank and will have optics. The ones towards the back will point straight down and will not have optics.

I had an hour after work and figured I'd do a to-scale version over the top down view. Each of these sinks will be mounted with two L-brackets and can be tilted as needed. Wiring will be hard to get looking good but I can do it. Trust me.

It's hard to get an idea of what this actually is without me there to walk through it...but I think its sufficient to say that it will be a combination of a PITA to build and WAY INCREDIBLY bright.

There are going to be three 'sections' in the tank. Right, middle, left.

Each will have control of the whites and blues in that section.

I plan on starting on one side of the tank and firing up the blues at 10% and then moving across the tank...raise those to 20% then bring on the whites. Those will come on across the tank as the blues continue to raise in intensity. Then bring them all back down at the end of the day in the opposite order. I'm sure it will take some fooling around to get it looking reasonable but I think it could be really awesome.

So you think I'm crazy?

 

[jgwinner]

I plan on starting on one side of the tank and firing up the blues at 10% and then moving across the tank...raise those to 20% then bring on the whites. Those will come on across the tank as the blues continue to raise in intensity. Then bring them all back down at the end of the day in the opposite order. I'm sure it will take some fooling around to get it looking reasonable but I think it could be really awesome.

So you think I'm crazy?

Yea. But I want to do the same thing

My only thought off the top of my head is that you may have overlaps and 'hot spots' but it looks like you arranged the strips specifically to do that and have the light angled.

I had a small idea the other day - instead of blowing a lot of money on LED's and drivers, most Arduino's have easy interfacing to R/C servos, so maybe I just hookup a motor and crank the fixture across the tank

I found a PWM shield that has more dimmer outputs, although your driver cost may add up. Still looking at alternatives to that myself. I think my relay idea is a good one but you could only light up a few at a time, not the whole tank for high noon.

== John ==​

 

[D5HP]

Yea. But I want to do the same thing

My only thought off the top of my head is that you may have overlaps and 'hot spots' but it looks like you arranged the strips specifically to do that and have the light angled.

Yeah... I thought about this too. I think I'll be okay though since I will be able to easily tilt the LED arrays around if necessary and since they are the 1W LEDs I don't think I'll be absolutely scorching anything even if I have 10 pointing at the same spot since some people are using MUCH higher output LEDs with good results.

My main goal is to have a really full and fluid coverage of the tank with minimal light being directed at the front glass.

I had a small idea the other day - instead of blowing a lot of money on LED's and drivers, most Arduino's have easy interfacing to R/C servos, so maybe I just hookup a motor and crank the fixture across the tank

I found a PWM shield that has more dimmer outputs, although your driver cost may add up. Still looking at alternatives to that myself. I think my relay idea is a good one but you could only light up a few at a time, not the whole tank for high noon.

== John ==​

Great idea...my concern is that I want a solid 4 hours of the day to be FULL lighting and I don't want to have to move my fixture around.

Servos are great for that sort of thing...if you want some more ideas PM me.

I have a pretty fair amount of experience doing that sort of thing and I'd be happy to help you out...especially since you're crazy too. :lolspin:

 

[4ddiction]

How many leds would i need to run for a 36''x13''x18 size tank?

 

[SC Reefaholic]

Money is in the bank and ready to order my Drivers. Want to make sure these arent going to be too much.

HLG-100-36B rated at 2.65A running 2 strings of 8 XP-Gs = 1325 mA each string

HLG-120-36B rated at 2.9A running 4 strings of 8 XP-Es = 725 mA each string.

My concern is that with the ELNs it has been documented that they are rated at 1.3 A but have put out over 2A when you run below their max voltage. Do the HLGs have the same issue. My forward voltage is only going to be around 28 - 30V so I dont want to have to worry about these things putting out excessive current and blowing fuses because I am not running them anywhere near their max voltage.

Anyone have any input or experience here?

 

[sammy113]

I'm planning a lamp with a friend and we'd like to use the XM-L neutral whites. What's the ratio that has worked better for this? 4:1? maybe

Also what's the best driver for them to get the max out of them?

 

[kcress]

I'm planning a lamp with a friend and we'd like to use the XM-L neutral whites. What's the ratio that has worked better for this? 4:1? maybe

Also what's the best driver for them to get the max out of them?

You sure you want to do that? We can't suggest a driver until you say how many and what current. I probably wouldn't "get the max out of them". As that might cause some serious spot-lighting and requires an A-game on the heatsinks.

Ratio? Depends on how hard you're driving them.

 

[sammy113]

You sure you want to do that? We can't suggest a driver until you say how many and what current. I probably wouldn't "get the max out of them". As that might cause some serious spot-lighting and requires an A-game on the heatsinks.

Ratio? Depends on how hard you're driving them.

Still not sure how many. We're trying to build sort of like a strip light for a 900g tank. Is currently lit by four 250w MH's on lumenarcs. Looking to use LEDs a couple of hours before and after MH's.

Initial thoughts were around 144 LEDs 2:1 ratio. Now looking to probably use less LEDs or more efficient. That being said, if we were to use 144 LEDs with a 2:1 ratio will use 48 NW. Hoping to use maybe half or 1/3 of those?

Current? don't know about XM-L. At least I'd like to run Blues somewhere between 750mA to 1000mA

Tank is 10' long x 3' wide x 4' high.

 

[jcgd]

Kress, or anyone who knows,
Can you comment on the spacing of xpgs that results in noticeable spotlighting? I assume the factors that result in spotlighting are the spacing, lenses, and fixture height? Is there an example of where you have seen spotlighting?

I'm trying to prepare for the results of my build. I will have four 6x12" pendants over my 165 gallon (72x24x22"). Each pendant has 7 XML that can be driven up to 2000mA. I have 40 degree optics and the fixture will be about 24" above the surface. I'm hoping the effect will be like metal halides but with less scatter. I want to get some shadows but I don't want to see each beam.

I seem to be a guinea pig for the XML.

 

[Virtuoso]

This is an absolute monster of a thread. I would just like to repeat what someone said earlier, you guys are doing an amazing thing for the hobby. Thing is, it is really difficult to piece together information if you are just jumping in, and reading 300 pages would probably make me blow my brains out. I am not an idiot, but I am not an Electrical Engineer, either. I saw a summary on page 171. Is there a more recent one, or even better, a "the leg bone is connected to the knee bone" version? It would be much appreciated. Thank you all again for all the hard work you have been doing on this.

 

[brassmonkyballs]

Kress, or anyone who knows,
Can you comment on the spacing of xpgs that results in noticeable spotlighting? I assume the factors that result in spotlighting are the spacing, lenses, and fixture height? Is there an example of where you have seen spotlighting?

I'm trying to prepare for the results of my build. I will have four 6x12" pendants over my 165 gallon (72x24x22"). Each pendant has 7 XML that can be driven up to 2000mA. I have 40 degree optics and the fixture will be about 24" above the surface. I'm hoping the effect will be like metal halides but with less scatter. I want to get some shadows but I don't want to see each beam.

I seem to be a guinea pig for the XML.

Rule of thumb I always follow is LEDs spaced about 2" apart and each row about 3". Should be no different for XMLs IMO.

You are correct in what causes spot lighting. Some people have done layouts with different degree lenses so perhaps they can chime in on height of fixture....Jimmy? you around?

 

[kcress]

This is an absolute monster of a thread. I would just like to repeat what someone said earlier, you guys are doing an amazing thing for the hobby. Thing is, it is really difficult to piece together information if you are just jumping in, and reading 300 pages would probably make me blow my brains out. I am not an idiot, but I am not an Electrical Engineer, either. I saw a summary on page 171. Is there a more recent one, or even better, a "the leg bone is connected to the knee bone" version? It would be much appreciated. Thank you all again for all the hard work you have been doing on this.

A common complaint. Suck it up... Read every page before you go to bed.

Or.


Go to TheFishMan65 home page where he keeps a summary up to date.

BTW where'd he get off to?

 

[kcress]

Kress, or anyone who knows,
Can you comment on the spacing of xpgs that results in noticeable spotlighting? I assume the factors that result in spotlighting are the spacing, lenses, and fixture height? Is there an example of where you have seen spotlighting?

I'm trying to prepare for the results of my build. I will have four 6x12" pendants over my 165 gallon (72x24x22"). Each pendant has 7 XML that can be driven up to 2000mA. I have 40 degree optics and the fixture will be about 24" above the surface. I'm hoping the effect will be like metal halides but with less scatter. I want to get some shadows but I don't want to see each beam.

I seem to be a guinea pig for the XML.

Sounds pretty good to me. Go for it. Do a build thread. Provide lots of pictures.

 

[kcress]

Still not sure how many. We're trying to build sort of like a strip light for a 900g tank. Is currently lit by four 250w MH's on lumenarcs. Looking to use LEDs a couple of hours before and after MH's.

Initial thoughts were around 144 LEDs 2:1 ratio. Now looking to probably use less LEDs or more efficient. That being said, if we were to use 144 LEDs with a 2:1 ratio will use 48 NW. Hoping to use maybe half or 1/3 of those?

Current? don't know about XM-L. At least I'd like to run Blues somewhere between 750mA to 1000mA

Tank is 10' long x 3' wide x 4' high.

10 x 3 x 144 / 16 = 270 XPG and XPE. Ouch.

If you were going to bother I'd replace the MHs entirely. Why keep dumping money into new bulbs all the time? And cooling and make-up water and cleaning the glass, etc.

 

[jcgd]

Still not sure how many. We're trying to build sort of like a strip light for a 900g tank. Is currently lit by four 250w MH's on lumenarcs. Looking to use LEDs a couple of hours before and after MH's.

Initial thoughts were around 144 LEDs 2:1 ratio. Now looking to probably use less LEDs or more efficient. That being said, if we were to use 144 LEDs with a 2:1 ratio will use 48 NW. Hoping to use maybe half or 1/3 of those?

Current? don't know about XM-L. At least I'd like to run Blues somewhere between 750mA to 1000mA

Tank is 10' long x 3' wide x 4' high.

Check out the BridgeLux BXRA-c4500. You could run them kinda like metal halides and supplement them with royal blue XPEs. They have a really nice, full spectrum colour to them. You'd just have to add blue to get the higher kelvin.

I know a guy who runs them at 25v at 2A. About 50 watts each. You need some serious heatsinking, but you wouldn't need a truckload of LEDs and a huge fixture.

Just something to think about. Link to his thread here.

 

[jkopp36]

I could use a little input if anybody has some left:

My LEDs will be 18-20" above the water line on my setup. It would save a lot of work and material if I did not shield them. It seems like it should be fine.

Thoughts? TIA

Reminder: 144 LEDs over 225g 72Lx30Wx24H

 

[jcgd]

If you never have water splashing up that high I wouldn't think it would be an issue. if there isn't salt creep around anything else that high than you should be safe.