DIY LEDs - The write-up

Status
Not open for further replies.
"~26V * 0.15 A = ~3.9W" Times three strings = ~12 Watts

There are something like 26 LED dies in there:

MPL-EZW.jpg


Stu
 
der_wille_zur_macht said:
First, the usual disclaimer that there really aren't hard and fast rules yet, but that said, most people are finding that if you stick with the typical LEDs (XR-E Q5 cool whites or equivalent mixed 50:50 with blues or royal blues, driven at 700mA) you'll need 24 - 36 to equal the power of a 250w MH. I'd go for the high end of that range on your tank, since it's so deep.

Your optics sound well chosen but it'll depend a bit on the height the LEDs are mounted above the tank. If you stick around a foot or so that should be OK.
Click to expand...

That's what I was thinking thanks for the input.
 
Don't sweat the anodizing. What everyone forgets is that bare aluminum - isn't. It oxidizes rapidly and will be covered with oxide even if it isn't anodized. So you might as well support the look and the durability you desire.
 
kcress said:
Don't sweat the anodizing. What everyone forgets is that bare aluminum - isn't. It oxidizes rapidly and will be covered with oxide even if it isn't anodized. So you might as well support the look and the durability you desire.
Click to expand...

On that note, I was planning on dusting the outside of my heatsink/fixture with a coat of white spraypaint and something tells me it will be just fine (of course not painting the contact area between the LEDs and the heatsink) :)
 
Interesting - News breaking story that even CREE has not released yet and no-one commented on that pic above......

I could light my entire 125G with just 20 of those.

Stu
 
stugray said:
Interesting - News breaking story that even CREE has not released yet and no-one commented on that pic above......

I could light my entire 125G with just 20 of those.

Stu
Click to expand...

LOL hey we appreciate the info, keep it coming if you will. IMHO when I saw the color temp and voltage required to push it I felt like it didn't really apply to my purposes so much. And then it's also less than 1/2 as efficient as the XPG's. I mean, what is the benefit to an LED running at low current high voltage?

Still though, it is great to stay tuned into the latest developments so keep them coming :beer:
 
Has anyone actually successfully used an Apex to dim their meanwells? I've found several references while using the search, but no posts stating someone was actually successful.
 
widmer; Paint? That will certainly reduce the heatsink's abilities. Too much? Too many variables to say. I can say that the LEDs will run warmer than without paint. Perhaps a few degrees. Do you care?

Stu; I'm with widmer.. ho hum.. Once the efficacy is noted and the lousy color. I can say that the color would be perfect for a turf scrubber! But then since a good turf scrubber runs about 18hrs per day you quickly come back to crummy efficacy hurting you pretty bad.


mm95z71; You aren't going to get six LEDs (18/3) lit up with any 12VDC and a BuckPuck.
 
mm95z71 said:
I'm wanting to make another LED array but much smaller. Plus I want to use a 12v power supply as opposed to the 24v I used on my big array. Can someone tell me if this power supply will be big enough to power 3 buckpucks running 18 LEDs? Thanks.

12v @3.5A 40W
http://www.mpja.com/prodinfo.asp?number=16001+PS
Click to expand...

Well you can only run 3 LEDs in a series on 12v (remember? ~3.5 + ~3.5 + ~3.5V = 10.5V any more LEDs and you go over 12v)

And the mantra has been don't run them in parallel either.

But pretend you had 6 buckpucks so that you could still do 18 LEDs because you can only run 3 per buckpuck @ 12v.

Then if you are running them at anything over 500 mA, you need more amperage.

For instance if you ran them at 1 Amp you would have 6 strings x 1 amp each = 6 amps used. So you would need a 6 amp power supply + breathing room = ~8 amp @ 12 volts.

Or 4 amp @ 24 volts. So why hate on the 24v supplies?
 
mm95z71 said:
Kcress, Thanks. I'm just going to stick with 24v and run 2 12v fans in series. Some people have complained of fan noise and I can't hear mine over skimmer/plumbing noise.
Click to expand...

Then buy a 3rd fan so that you are running 3 in series so that each gets 8 volts and runs slower and quieter. (24/3 = 8)
 
Has anybody ever actually stacked up these fans in series? Does it actually work? These fans are fully electronic. They aren't just raw wire-motors. I think the electronics actually switch ON and OFF on them. What is the voltage seen by the second one in a string when the first one shuts off? 24V? What do the electronics think about that?
 
FWIW, my longest-running nano prototype fixture has two fans in series on a 24v supply. It's the fans that come on these heatsinks:

http://www.mpja.com/prodinfo.asp?number=17045+HK

They are typical 3-wire fans, and I ignore the tach wire.

If the fans had some internal control that was switching them on and off, what condition would they leave the power connection in when off? I'd imagine it would be open. If the "off" mode closed the power connections with no resistance (which it seems like you're assuming?), wouldn't they essentially short the power supply? Which would leave me to thing that that wasn't true.
 
kcress said:
Has anybody ever actually stacked up these fans in series? Does it actually work? These fans are fully electronic. They aren't just raw wire-motors. I think the electronics actually switch ON and OFF on them. What is the voltage seen by the second one in a string when the first one shuts off? 24V? What do the electronics think about that?
Click to expand...

I've already got the 3 fans I'm using. They're all the same model, a cheap 60 mm computer fan from ebay for like $3 ea. I've had them in series on both an 18v and a 12v power supply, just fine albeit not as quiet as I'd prefer.
 
stugray said:
Interesting - News breaking story that even CREE has not released yet
Click to expand...

I haven't said anything because those LEDs are so far outside our norms (drive current, voltage drop, density, etc.) I'm having a hard time wrapping my head around them. :D I hate to be a pessimist, but these are my thoughts:

1) Yes, the efficacy is lower than the typical Q5 XR-E Cool white, but it's actually pretty close to the typical good warm white LEDs which have lower efficacy than cool white, most of the time.

2) Like I mentioned above, driving these would be a challenge for those who want to stick with the typical buckpucks or meanwells, since the drive current and voltage are different from what we're used to.

3) I would worry about "energy density." I'm probably abusing that term, but that's a LOT!!!! of light from a single point, even with the wide viewing angle. And, it would be a LOT of heat from a single point! We're used to 3w from a single star board. I've used some 3-up Rebels in my designs, which maxes at like 7 or 8w from a single star. They work fine on a nano build, where you can put them on a massive heatsink and you don't need to spread the light out a lot, but think of the resolution on a large tank. Instead of 150 XR-E, you might have 20 of those. With the 150 XR-E, you're going to get even coverage of the tank. With the same amount of light coming from just 20 points, I'd wonder.

4) Plus the color temp, as others said.

It'll be interesting if they release a cool white version of that LED.
 
Status
Not open for further replies.

Similar threads

R
DIY AI-coded ESP32 based aquarium controller
Replies
0
Views
308
ronnyking
R
AquaticReefTV
DIY Cable management time lapse
Replies
1
Views
531
S|\/|S
S
AZBigJohn
New Build... I'm back
Replies
15
Views
447
Dustin07
D
B
Beam Deflection - 15 years and I finally broke down and wrote a how to.
Replies
16
Views
915
BeanAnimal
B
A
Fleece filter bypass problems (Innovitech X filter)
Replies
1
Views
39
Vinny Kreyling
Vinny Kreyling
Back
Top