DIY LEDs - The write-up

[skippyreef]

COuld you point me in hte right direction to get one of the holders to test with???

 

[shackscs]

Your local Radio Shack, unless you need a lot of other stuff suff as wire, solder, etc.

If so Mouser.com is a god choice to grab all that you need.

 

[nitjt]

Neogenocide where did you get and what size nylon screws did you use? Can you get the LEDs down snug enough with them? I wanted to use something self threading so I would only be drilling pilot holes not taping threads.

 

[der_wille_zur_macht]

Nylon fasteners are NOT going to self-tap in aluminum. You'll need to either thread the holes, or drill them through and use (nylon) nuts and washers on the backside.

 

[Skeptic_07]

what are you guys using to test the LED's to make sure they work prior to using them????? Once they are down with the epoxy my understanding is it is forever.

I use my multimeter to test individual LED's using the diode tester function.

The epoxy is certainly NOT forever. I don't know where this idea came from. Yeah if you make a mistake it will be a PITA to fix it, and probably won't be so pretty looking, but it is definitely not THAT permanent.

 

[TheFishMan65]

FWIW I talked with an mechanical engineer. He would NOT recommend nylon screws to hold LED to a heat sink. He could not point to any specific data, but he felt that they would not hold tight over time.

I admit another mechanical or EE may give a different opinion, but to date this is a close to I have an expert opinion.

 

[der_wille_zur_macht]

Worst case, if the epoxy leaves residue behind, you could just offset the replacement LED 3/4" to one side or the other. Probably won't make an ounce of difference on a large array.

Interesting that the discussion has gone in this direction. I've screwed every single LED I've used to date. It's been easy because I have a drill press. However, I'm on the verge of picking the 10mm square MCPCBs from Cutter for my big tank, so I'll either have to come up with something creative or switch to an adhesive.

 

[The Grim Reefer]

I was going to use nuts and bolts but I also bought a bunch of those small heat sinks. The plan now is stick them to the aluminum channel behind the LED's, figure it couldn't hurt, especially if it makes the difference between needing fans and not so it was either trying to use self tapping screws or use adhesive, decided to just go with the pads. Costs more but should be easier to R&R oopsies. But being the almighty Grim Reefer we KNOW I will never make a,,,,, Damn, I couldn't even finish typing that.

 

[MontyJack]

Hi folks,

Will this work?

The tank is 59x31x31 inch. The light color should be traditional like SoundWaves first build 1/1 CW RB ratio.

I will use:

56x - XPGWHT-L1-1A0-R5-0-01 driven by 5 ELN 60-48-d (14 LED on one driver)

70x - XPEROY-L1-D40-16-0-01 driven by 4 ELN 60-48-d (14 LED on one driver)

All LEDs should get 36 deg. optic, rippled from Carclo. The pendant will be 15’’ to 20’’ above water surface. The height will be adjustable.

Is this enough LEDs/light for that big and deep tank?

Is the XPG/XPE ratio right to gat that traditional actinic look?

Thanks Monty

 

[der_wille_zur_macht]

Monty, very few people have built a rig with the LEDs you're suggesting at that large of size, so the best we can do is extrapolate.

But, extrapolating, I'd say you're in a good range. FWIW my 360g will probably end up with 70 - 80 cool white R5 XP-G and 100 - 120 royal blue XP-E, with the same optics you're talking about, mounted ~22" up.

Putting 14 LEDs on each meanwell - it's gonna be a reeeeeall tight stretch for the royal blue XP-E since they drop 3.4v at 700mA and 3.5v at 1000mA. You might want to stick with 13 per, otherwise you might end up inadvertently under-driving your LEDs. The XP-G drop 3.2 - 3.3v at 700 - 1000mA, so those SHOULD be OK, but you still might end up with a string that has a higher-than spec Vf which would mean trouble. FWIW, people have found pretty significant margins of error on LED Vfs so IMHO it is prudent to build in a bit of extra capacity.

 

[crvz]

Can someone tell me more about a good thermal tape? I'm using the LEDs for supplementation, and may chose to move them around until I get the right combo, so I'm leaning towards using the tape in lieu of the epoxy for now. Is this something I can get at radioshack, and is there a good/better product to use over another (I'll have to weigh performance vs. removing the tape on some level)? Also, is this the precut tape folks are using when they want to be exceptionally lazy?

 

[MontyJack]

Der wille zur macht, it is nice that one of us can always count on a good and detailed answer from you.

You are right with the XPEs and the drivers. I have to try it out. In the driver datasheet is mentioned, that the driver is capable to support a higher voltage. I will see?! If it's gating to hot I will take off one star ore more in the test array.

By this point, has anybody experience with gating higher voltage from the MW ELN 60-48 drivers?

Anybody else who is about to get the right mix of XPG/XPE ore has already done it???

Thanks

Monty

 

[der_wille_zur_macht]

Can someone tell me more about a good thermal tape? I'm using the LEDs for supplementation, and may chose to move them around until I get the right combo, so I'm leaning towards using the tape in lieu of the epoxy for now. Is this something I can get at radioshack, and is there a good/better product to use over another (I'll have to weigh performance vs. removing the tape on some level)? Also, is this the precut tape folks are using when they want to be exceptionally lazy?

That is the correct precut stuff. Here is the same material in uncut sheets:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=BER246-ND

Basically, you want something purpose-designed for thermal transfer, not just any old two-sided tape. If you want to compare other products, you can get the datasheet from that link for the Bond-Ply material and compare adhesion and thermal performance numbers.

You are right with the XPEs and the drivers. I have to try it out. In the driver datasheet is mentioned, that the driver is capable to support a higher voltage. I will see?! If it's gating to hot I will take off one star ore more in the test array.

The higher voltage covers the adjustment range for the voltage adjustment pot, which is essentially meant for running in constant-voltage mode near 48v output. We want the output to be regulated by the constant-current functions of the driver, not the constant-voltage functions. So if you strive to eek every last bit of juice out of a meanwell, turn the voltage adjust pot all the way up to ensure that limit does not interfere with your string of LEDs. Then adjust the current as normal. Finally, test for current on the output side to make sure you're actually getting the current you think you're getting at the LEDs. I wouldn't just be worried about damaging the driver, I'd also be worried about inadvertently under-driving the LEDs. Basically, when the driver is working in constant current mode, it increases or decreases voltage as needed to keep the current at some predetermined target value. If a given string of LEDs needs more voltage than the max the driver can provide to reach the target current, it won't regulate properly and your LEDs won't get the current you think they're getting (and/or you'll damage the driver, or it'll hit some internal limiter and shut off, etc.)

 

[crvz]

Alright, last ignorant question of the night. On the meanwell driver, does the polarity of the AC input matter? There are two labels (ACL and ACN), do I need to worry which one goes to hot and which to neutral? I assume not, but I'd hate to find out the hard way.

 

[TheFishMan65]

I haven't used them, but from what I read it does not matter. However, if you have a multimeter (or other tester) you can find the live and neutral line. REMEMBER THIS 120 VOLTS. Measure the voltage from each of you AC line to ground. One should measure 120 (live) and the other 0 (neutral).

 

[rickb]

Hey,

How hot does the meanwell get, I built my fixture (2 fixtures of 48 led, 50/50) for my 90, but I'm trying to decide whether to put the meanwells in the canopy or above the canopy which is actually end up being 3-4 feet wire distance from the fixture.

 

[HeneryH]

Alright, last ignorant question of the night. On the meanwell driver, does the polarity of the AC input matter? There are two labels (ACL and ACN), do I need to worry which one goes to hot and which to neutral? I assume not, but I'd hate to find out the hard way.

Many of us have been assuming that AC-L was "line or black" and AC-N was "neutral or white"

 

[TheFishMan65]

That also work if you have those color in your power cord (and they wired it right).

 

[stugray]

"Measure the voltage from each of you AC line to ground"

There is no ground in the meanwell drivers.

If you have a green wire, it is not hooked to anything inside the box.

Besides, how can you measure voltage looking into the meanwell?



The meanwells give off no discernible heat at all.

Stu

 

[Dannyrotorpilot]

NEwb needs help

NEwb needs help

I started reading this thread yesterday and woke up this morning and all I can say "information overload" but this is one of the best threads Ive seen in a while. Way to kick Orbital in the rear end! They blanket patent LED use in aquarium so everyone goes out and makes their own! Thanks Orbital for driving ingenuity from the average DIY'er! Awesome job guys, just plain awesome work seen thru the pages of this long thread. Strong work!

Having said that, I am putting together a 180 Gallon SPS / LPS Mix and am dead set on building my LED setup. 72x24x24 tank. I was going to run 3x 250W MH but now want to run three LED pendants but am overwhelmed with the amount of info. Can someone please be kind enough to guide me to what they would use to run a replacement to (1) 250W MH 15K. Sort of a grocery list. I have most of the thread but am confused because we started off with Buckpucks and powersupplies and now I see just the use of Meanwell Products. Even a wiring schematic including the Meanwell would be very helpfull. I Want to use Cree LED's and like the Meanwell product. Seems like a nice clean install. I will be obtaining my heatsinks from Heatsinkusa.com.

Any help would be greatly appreciated!:dance: