Simple multi-chip LED

[TheKraken]

I am interested in adding LED for color but want to do something slightly different with a multi-chip LED. In particular it is possible to order a DIY "kit" with the major components. The highlights are a 110V AC to ~36V, 1.5A dimmable driver (some of the others are 12V DC FYI) and a simple Epistar 50W chip with custom color. To make white the first step is to acquire a blue emitting chip (~450nm here) and add a phosphor coating for white (ie secret sauce). In this case 3 rows are cold white and 2 are just blue. I was hoping that this would have (or be modified) for 5 channels (IE the Dream Chip) to drive the blue OR white but this is the standard single channel so all on.

So far the kit is complete as pictured. I should note that instructions were not part of the kit and none were included in the box.

* As this will be hanging I have to locate some artic silver thermal adhesive or modify the black CPU holder (working on this)
* The driver needs to be wired with a 110V plug and again with a wire for the DC side
* I am debating using a ~400ohm resistor to drive the fan at ~8V or set up a separate DC loop for fans
* I used IC Gel for the lens and have some haze to clean up
* The fan fits in a 4" PVC tube so I am considering building an enclosure (mostly for noise)

Anyone else with a multichip yet?

 

[TJL]

Very COOL Paul, cannot wait to see how it all plays out. Are you going to run it with a controller to Ramp-up / Ramp-down since its a dimmable driver ??? Will have to do some further research on the multi-chip emitters, been awhile since I finished my build.

Cheers, Todd

 

[dhnguyen]

I'm interested to see how this works out as well. Been thinking about jumping on LED myself but to be honest I haven't been all that impressed with the spread and coverage.
Maybe the multi chip would be better?

 

[1guydude]

Plasma! Lol
Kool build paul.
I'm looking at a 50w led chip with no optic correct?
Can't wait to see it in action.
D

 

[tat2z_21]

My last build was with 3x 100w multichip LED. The collminator will not be necessary. I promise you those things pack more punch then what is needed. The reflector will minimize spill, and direct an abundant amount of light into the tank. I had 3 cool white over a 180 with color enhancing 3w'ers surrounding it.



Tis is the tank lit at 35%

 

[tat2z_21]

I'm interested to see how this works out as well. Been thinking about jumping on LED myself but to be honest I haven't been all that impressed with the spread and coverage.
Maybe the multi chip would be better?

IMO your experience with the spread of LEDs is because of the unnecessary use of optics. Unless the depth of your tank is 30" or more optics are really not necessary. Again this is just my opinion.

 

[dhnguyen]

Do you have a build thread on this?

 

[tat2z_21]

I did not do a thread but lots of people seen what they looked like and the intensity of them. People state that the multichip efficacy is higher, and the efficiency is lower. However, when comparing electricity bills of Metal halides and the 100w'ers I would go with the multichip's every time. My electricity bill dropped a good 45 dollars, and the tank was able to stay cooler.

 

[tat2z_21]

I do have a video of them running though.

180 gallon 3x100w Multichip LED - YouTube

 

[senji]

video no worky?

 

[tat2z_21]

Huh video works for me. Somebody else out there give it a try, let me know.

 

[tat2z_21]

YouTube

Try this. It works for me every time.

 

[dhnguyen]

You have to select Desktop. The link defaults to mobile

 

[dhnguyen]

That looks pretty nice. Curiously why didn't you add any color enhancing LEDs with the center light?
Nice wave action as well.

 

[1guydude]

Worked for me.
Kool tank and shimmer... like the niger triger and the.sps next to the nem.
Lol


Sry for hijacking kraken.

 

[1guydude]

So ppl say led chips r overkill?
Wat about 5w leds?
D

 

[tat2z_21]

Actually the 3w'ers were a mix with red, neutral white, the blue was enhanced with my 110w VHO's

 

[tat2z_21]

The 5w'ers can be used, I don't see why they couldn't. The problem with the 5w's is the availability of colors, but I once built a unit using two rows of 6, 5w neutral white, and four rows of 3w royal blues total of 24 Rb's. The light was intense. I don't use optics, to eliminate the strobe effect.

 

[TheKraken]

Todd,

I told you I was keeping this SIMPLE : ) The system is 2x 50W LED with a dimmable constant current supply from a kit and so far I have;

* Modified the black mount to accommodate chip and lens.
* Bought and become familiar with a crimp tool. (120V cable into the black project box with a junction bar to power both LED drivers.)
* Solder the drive leads to the chip (I did not need to lengthen them for this hood)
* Adapted existing 12V icecap variable speed fan power supply to drive both fans at 12 V. I have a potentiometer to turn down the speed but it will be in the room with the skimmer anyways
* Mounting is 2x holes (~70 mm) in a wood "Halide" canopy. I am using standard gravity mounts.

Thoughts:
* Ordering/buying/borrowing artic silver thermal adhesive (the 2 part) would have reduced the complexity of re-jiggering the black mount (enlarged, mounted backward, original screws had springs and locking device....)
* Piggyback the fan to the drives by making ~9 V with a 5W 330ohm resister of so. (RadioShack did not have the part in stock)
* One of the dimmers dun blowed up (factory clearance issue) so I dim both channels together.
* It seems like I got exactly what I paid for. In this case "instruction" or "spec sheets" were not included. Not that finding the drive current for the fan is hard (90mA), it is just not included in the box.
* The fan is blowing out (from the chip) and I would rather reverse to keep salt air out of the fan. Running -9V does not work and the mount is not symmetric so I will revisit later or on the next design.
* The fans are nice as the heatsink was getting warm during testing. I would like if the fan was powered off the same driver or at least the 120V line to limit the chance the fans are not turned on. My impression is that this size of heat sink MIGHT be able to provide passive cooling at 50 W with the fan off. A heat pipe type heatsink might be able to provide passive cooling http://www.pa-international.com/images/stories/heatpipe-heatsink.jpg

So power on tests show that the illuminated area is roughly a square (the shape of the lends holder) at the base of the canopy/(top of tank) with a diameter of ~12" at a distance of ~12". The tank is a 120 (2x2x4)

The light is a very crisp blue but the canopy is already fitted with a pair of 4' VHO lamps that I may use for growth/color.

SO
* If you want two channel (Blue and White) buy the "dream chip hybrid" or mix actinic AND white chips. I am thinking 1X, 50W, 20000k white and 2x, 20W actinic per 2'.
* For control geeks: Power supplies can be constant current or constant voltage. This dimmer is a 10 turn potentiomenter (only 1 turn from on to off) and it will not dim to zero or reliably turn back on if you are below some threshold. My next build will be constant voltage with the LDD style PWM dimmer. These dim to zero and are infinity controllable. Think of it as a mini driver where you have one power supply (ie 42V) and then a specific LDD driver based on current. I would use 1.5A in this case per 50 W chip. A 20W would be 600mA for example.
* The way color works here is that all the emitter are blue (450nm?) with a phosphor applied to down convert to white. The vender buy a blue chip from Epistar and then makes it a white chip as far as I can tell. The "while still has A LOT of blue left.
* If you really care these are Epistar LED. I believe the 38 um package which is rated at 400mA and I am driving ~ 300mA (ie 1.5 A in 5 parallel chains) The 42um is rated at 700mA so watch out as you can "overclock" some of the chips as they are rated at 50x emitters @ 1W each but can be driven to 3W each!

 

[TheKraken]

I was near a par meeter last night and each lamp at full power is >3k PAR at 1" (apogee meter is maxed), ~1200 at 1' (ie the water surface) and ~250 at 3' (the sand bed). Time to finish the rest of the tank. It just needs plumbing, rocks, and water now.