LEDBrick Project - DIY pendant w/ pucks

[theatrus]

I'm planning on running more tests on the 8/16 LED boards. If my pricing holds, the Luxeon Z emitters are less expensive than you may think (more than a Chinese sourced LED, but less than the XP/XT/Rebel packages). Feel free to PM me for some information - as I'm working on the prototypes I'm happy to share at-cost boards so others can test as well. I have ~ 50 boards of each variant from the initial run, but not enough LEDs for them all Unlike some others, my sourcing and final manufacturing is currently all US based (being the location of my garage ).

 

[McPuff]

I have to ask what many are likely wondering... are you going to sell fully produced units? Or just components? This stuff is very cool. Very impressive.

 

[Fish4ead]

OK, a 16 up/4 channel unit would be perfect in my opinion. With the right emmiters you would be able to achieve almost any color you wanted in the tank. Your doing some incredible work here! Great insight and as fast as I can tell an almost unmatched creativity.

 

[theatrus]

I have to ask what many are likely wondering... are you going to sell fully produced units? Or just components? This stuff is very cool. Very impressive.

Since most folks won't have a reflow oven, I'll do all the soldering . In the nature of DIY, I'm happy to produce assemblies and kits for forum members at this point. My speciality isn't sourcing mechanics and pretty housings (though my original one wasn't terrible by any means).

 

[theatrus]

In case you were wondering, yes, it does fit on a T slot makersled heat sink. Not with the four corners I had intended but good enough.

Apparently the HeatsinkUSA T slot and the Makers T slot are different enough

 

[theatrus]

I did some testing with the Fredfish special to figure out how to better quantify light mixing quality.

First, the setup, mounted on a Maker's Slim heatsink (works great)

The LED puck is 12 inches away from a 98 bright sheet of paper (not all square and level, I'm still prototyping the setup ). Held in front of the paper, at 2 inches (so 10 inches from the light source) is a steel mini ruler.

In order to check the spacing/mixing, I took several shots nearly-on-axis with the LED (just above) with a 100mm macro lens at F4 (which throws the ruler out of focus). All four channels are driven at 500mA.

The first shot is the bare LED board, no reflectors and lenses:

The second shot is with the reflector and acrylic diffuser mounted on top:

No, the shot is not just out of focus. Also, the second image auto-exposure shutter speed on the second image was 1/320 vs 1/200 on the first, about 1.6x the amount of light (camera meters are also horrible at exact light levels, but its an interesting fact).

 

[theatrus]

Max PAR measurements (using SQ-500 (which reads blue LEDs *lower* than the normal SQ-120), at 1 amp, about 19W total, 12 inches, on axis) for this setup are:

100 naked LEDs
210 with reflector + diffuser
340 with reflector

Using a hacked FLIR E-4 (so full IR resolution), top-of-die temperatures were reading about 65C. Considering this will undershoot the max temp, Tj is probably in the 70-80C range, which is fantastic. Heatsink without any active cooling in a 25C room is at about 34C.

 

[theatrus]

Repeated the test with the 16-up Luxeon Z board:

No reflector

Reflector WITHOUT diffuser

Reflector WITH diffuser

As for PAR, with all LEDs at 1A (all above setup applies)

230 naked LEDs
460 with reflector + diffuser
830 with reflector

Using the FLIR, I'm seeing about 100C die temperatures (with ballpark correction) - this is still in the acceptable range. The heatsink was actively cooled, and 2x as much power is going through this setup. I'm going to confirm with a thermocouple attached to the lead/pad in a bit and use the thermal equations to confirm.

In this scenario, the Lime LED is technically overdriven at 1A (specified 700mA max). The deep red LED is also in a poor efficiency region. I don't suggest driving at full 1A power since the output is quite intense.

 

[Halo_003]

Very interesting how much better it blends with the diffuser.

Yup! The metal core PCBs used for LEDs are a bit more specialty, but its a LOT more common to get them from Chinese outfits.

Step 1 is to design the board. Common in the DIY / Hobby community is Eagle, but you can use KiCad, DIPTrace, CircuitMaker, etc. For LEDs, make sure the board is single layer and no soldered components going through the board.

As for making them, once you have the design files (commonly Gerber files + NC drill file, lots of tutorials for the various software on how to export that), do a little shopping.

For low qty (3) small boards, I love using OSHPark.com, the boards are a nice purple, its a US business and uses US manufacturers. Support and quality are excellent. Free USPS shipping and you get to collect all their stickers They however will not do metal PCBs.

For standard PCBs, you can check all the prototype volume pricing pretty easily with http://pcbshopper.com/

For metal PCBs, I've used both PCBway.com and Gold Phoenix (both China). Both have online quote forms once you know the rough size.

This is great info, thanks so much! I really appreciate it, I'd love to give this a shot at some point.

 

[Fredfish]

Max PAR measurements (using SQ-500 (which reads blue LEDs *lower* than the normal SQ-120), at 1 amp, about 19W total, 12 inches, on axis) for this setup are:

100 naked LEDs
210 with reflector + diffuser
340 with reflector

Using a hacked FLIR E-4 (so full IR resolution), top-of-die temperatures were reading about 65C. Considering this will undershoot the max temp, Tj is probably in the 70-80C range, which is fantastic. Heatsink without any active cooling in a 25C room is at about 34C.

Cool! Having more smaller clusters probably increases the cost of heat sinks, but gives quite a bit of flexibility in cooling including passive cooling in all but the hottest months of the year.

Comparing this to your 16 up Luxeon Z cluster, it looks like the Fredfish special will be almost the same as the 8-up Z cluster. It will be interesting to see how those two compare.

 

[theatrus]

Cool! Having more smaller clusters probably increases the cost of heat sinks, but gives quite a bit of flexibility in cooling including passive cooling in all but the hottest months of the year.



Comparing this to your 16 up Luxeon Z cluster, it looks like the Fredfish special will be almost the same as the 8-up Z cluster. It will be interesting to see how those two compare.

Probably similar, or at least in my measurement uncertainty range. The lower temps on the 8-up may improve output slightly, assuming we loaded the same mix of LEDs.

 

[theatrus]

No updates just yet on the 4 channel 16 up build in the 20k color scheme.

I'm going to also build the "ultimate violet" 8 up board. A wide array of every Luxeon UV from 430 to 380nm. It will also cost a fortune (sorry, can't get it any cheaper. luckily the LEDs are extremely efficient at the top of the range)

Spent the day swapping my 7 year old PanWorld out for a Vectra M1. I don't know why I didn't swap years ago since the noise level dropped about 10-20dB in the room. Worthy upgrade, even if I at first did the most amateur possible plumbing mistake possible, luckily I had ordered the BST to slip PVC adapters since I messed up ABS gasket adapters (didn't slip on the retaining ring when gluing, and it won't slide over any other plumbing couplers).

And back to our normal LED schedule.

 

[Poseidon]

That violet will be quite a wallet buster, what do you expect the advantage to the tank will be with such a powerful violet?

 

[Fredfish]

That violet will be quite a wallet buster, what do you expect the advantage to the tank will be with such a powerful violet?

He'll be the only kid on the block to have one? :lmao:

 

[theatrus]

He'll be the only kid on the block to have one? :lmao:

Think of it as a few years worth of actinic T5s

That one is more for kicks.

 

[Foggman]

What to you think of the bridglux 3w LEDs commonky found on the "chinese" fixtures?

 

[theatrus]

I've always wondered if those are actual Bridgelux units. Bridgelux specializes in GaN on Silicon chips which are their special sauce and much cheaper than the normal sapphire substrate for blue. As for packaged units, they really only market white COB modules, at least domestically. http://www.bridgelux.com/products

Someone in China can take the actual chips and package them of course, except Bridgelux specializes in lighting so they will be 450nm only units. I am unsure if Bridgelux sells phosphor coated chips, so who knows what phosphor you might be getting.

The other brand I see a lot is Epistar, which is a Taiwanese local manufacturer. http://www.epistar.com.tw/_english/01_product/07_search.php. They make several spectral points, but no violets (despite seeing vendors claim stock they selling are Epistar 420nm, at $0.50 a package )

SemiLEDs makes actual violet LEDs. http://www.semileds.com/UVLED_SemiLEDs.htm. There was a patent lawsuit between Cree and SemiLEDs that settled in favor of Cree, barring the import of certain SemiLEDs products. I don't know which are covered.

In short, I have no idea if those LEDs are actually Bridgelux or a knockoff or a totally different die branded as Bridgelux because it's a familiar name.

For a fun read on this branding problem but with SD cards: http://www.bunniestudios.com/blog/?page_id=1022

Also tangentially: https://m.youtube.com/watch?v=CPEzLNh5YIo

 

[theatrus]

And to finally answer: I really liked the Bridgelux Vero COBs I've experimented with. Very high CRI. I'm not sure what the Chinese fixtures are using. I am not an expert on LED dies and packaging, and likely not be able to make any determinations, but I'm always interested in taking things apart to see the guts.


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[Foggman]

but I'm always interested in taking things apart to see the guts.


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that is exactly why i asked, somone gave me a fixture that the drivers failed on (the dont like to go swiming) so i took all the LEDs off of it,

 

[Maryland Guppy]

I am well versed in these cheap Bridgelux and Epistar 3watt LED's.
20 beads from China @ about $4 and free shipping.
It is a crap shoot though, Kelvin is usually close, any under 420nm don't seem to last even if under driven.

I have several homemade pucks running on LDD's
Replaced 6-385nm and 4-3300K beads within the year.

The lens on the 385nm seem to melt and wrinkle even with PWM dimming @ 65% duty cycle.

The warm whites are strange they short out and either emit very dim or not @ all depending how many beads are in series.