HI Mike Thanks for bringing your LED to the swap and showing us, sorry i didnt get time to see it more. Unreal how bright they are.
brent

No trouble at all Brent, there wasn't much more to show. All I was able to do was get a couple of them fired up at your place, one blue & one white. It was a busy venue!

For what it's worth, I made a few photos of the set up over my tank this afternoon/evening. I'll try to get several more tomorrow with the T5HO & Halides for comparison, but just looking at the photos compared to real life, I must admit the photos don't really tell the story. Seeing the LEDs over the tank has given me more incentive to finish up the build & replace the old lights. Anyhow, here they are:

All LEDs running with the fixture 7 inches above water surface. Blues & Royal Blues set at 8 VDC, Cool White & 10000K White set at 9 VDC. So in effect they are all being driven at somewhat below their maximum forward voltage. Still very bright & the colours are blending nicely. Did not perceive any disco ball effect.

https://public.blu.livefilestore.com...80e.JPG?psid=1

This one is only the 5 Blues on the center rail dialed down low, set at only a few volts with the heatsink fans barely turning.
https://public.blu.livefilestore.com...85e.JPG?psid=1

that looks great , should be cool if you get into programming/controlling the diff lightings.

Yeah, I don't have a controller at the moment, not sure I want one either. Current lighting is on digital timers & I was thinking the same with the LEDs. This is one reason (aside from the wattage requirements) I need more power supplies, so I can run each colour with it's own power supply on separate timers. But now that I've started toying with the dimmers, a more sophisticated/automated method of controlling & dimming the LEDs is certainly tempting. On/Off with just a timer might not cut it anymore! Not that the livestock will care, since it's all been doing fine without sophisticated controlling.... more for the hobbyist I guess! I simply can't get that excited over fixtures that offer overkill features like cloud effect & lightning etc. I love my EcoTech VorTech pumps, but could care less that the Radion lights can communicate with them. What the hell for? Dawn/dusk dimming would make me a happy camper, don't need any more than that. 'Want' & 'Need' are different animals, often associated with large variations in $$$$$.

Decided to forge ahead & start using this fixture even though there's still a fair bit of work & experimentation ahead. A major part of the experimentation is of course how my critters react to the lighting change. Burned the midnight oil last night, pulled the old MH/T5HO monstrosity & hung the LEDs. Running them as is, with loose wires all over on only one power supply & 3 dimmers has it's limitations, but I figured the sooner I get started, the sooner I'll see how the livestock fares. The LED configuration with respect to numbers & colours is where I intended for the initial trial, so damn the torpedoes.

I started with the fixture approx. 12 inches above water surface this morning. The 12 volt power supply, set at just under 10 volts is on a single timer & changes in intensity are done manually, either with the 3 dimmers or raising/lowering the fixture. I cut some wooden wedges to mount the outer rails, giving them a 10 degree inward tilt. I'm hoping the increase in focus to center, away from the sides translates into less glass cleaning! I'll probably be moving the outer rails a fraction closer to the center to further tighten light spread & minimize spill over the sides where it's neither needed nor wanted. The Hagen 77 gallon is relatively narrow & my rock scape with corals runs pretty much down the center longitudinally. It will take some tweaking to find the sweet spot of LED spacing in conjunction with height above tank, but I don't think I did too bad with my initial guess in that regard.

The fans are definitely audible & although lower in noise level than those I had cooling the ends of my overdriven T5HOs, some of them have a mildly irritating high pitched whine. This may be due to the fact that they're running below rated voltage or simply because they're cheap, dunno. The more I bump up the voltage on the LEDs, the faster they run & actually quiet down a little. Might try cutting all the fan leads & running them full speed at the rated 12 volts to see how that works out.

I like the look, plenty of shimmer & great colours on the coral. The tank is more accessible since the fixture is mounted higher than the old set up. The fishes certainly noticed something was different this morning and were a bit shy, but in less than an hour they were behaving pretty well as usual. I have a spawning Maroon clownfish pair so it will be interesting if the lighting change has any impact on their schedule. It's been about 4 days since their last clutch hatched and the female should be about ready to put down another.

After a couple of hours, I lowered the fixture by 2 inches to 10 above surface & bumped up the voltage on all 3 colours of LED. That'll be my sophisticated, high tech dawn/dusk program until I get more power supplies & timers. Numbers are now as follows, measured at the input & output of each dimmer:

LED colour, Dimmer input VDC, Dimmer output VDC

10000K & 6000K White, 9.63, 7.98
Royal Blue, 9.73, 5.51
Blue, 9.83, 5.51

Not entirely sure why the difference in input voltage values, since a single power supply is driving all the dimmers & lights. I assume it's due to slight variations in wire lengths feeding the dimmers & probably the different number of LEDs being run by each dimmer. The dimmer running the Blues is driving only 5 LEDs, Royal Blues number 8 for that dimmer & the one working hardest is the dimmer running both the 10000K White & 60000K White which total 14. I'll have to keep an eye on that one since it's probably close if not over it's 8 amp limit. Haven't made any current measurements, but by underdriving the LEDs with the low forward voltages, they won't be drawing anywhere near their maximum of 1 amp, so should be fine.

Inserted my power monitor into the circuit & the fixture with voltages as set now is drawing 140-146 watts. Should equate to some useful energy savings over the long term, although it seems that my heaters will be running a little longer without the Halides doing their thing during the midday lighting period.

Update time! Cleaned up excess wiring & secured it to safely continue using the fixture. So far it's working great with no duds & I'm able to blend/control the colours nicely with the 3 dimmers. I've ordered 2 more dimmers to split the 6000K whites from the 10000Ks. I'll be ordering at least two more power supplies to distribute the load & run each colour on a separate timer. The current config works fine until those parts are in, it simply means I need to manually adjust the intensity for dawn/dusk dimming every day. Colours on separate timers will allow basic dawn/dusk effect, but automatic dimming using additional electronics is something I'm contemplating for the future.

12VDC, 250watt power supply & three 8amp dimmers are now mounted on a board in the center compartment of the stand. Another dimmer will be added to isolate the 6000K whites from the 10000K whites. 14AWG single strand house wiring runs from power supply to dimmers. From dimmers up to fixture is 14AWG stranded hook up wire.
https://public.blu.livefilestore.com...05E.JPG?psid=1

Top side of the fixture. Added 4 cedar slats to mount terminal boards for wire distribution. Drilled additional holes in the rails for rubber grommets to feed LED wires thru.
https://public.blu.livefilestore.com...08E.JPG?psid=1

Ten of these 12 to 24VDC, 900mA constant current drivers for 10watt LEDs came in last week. Don't think I'll be using them on this fixture since there doesn't appear to be any adjustment on them. I test fired one on a spare 10watt LED & it worked great at regulating the current as advertised. Haven't tried running it downstream of a dimmer to see how it reacts to that, but even if it works, I'd need one for every LED & that would be a bunch more hardware to add to the fixture. Since the build is essentially a parallel hookup, with each LED seeing the same voltage as delivered by the dimmers, constant current is less of a requirement than for a series application where you're feeding a string of LEDs. They might still come in handy for when I set up a fuge or frag tank, since there's really no dimming requirement for those applications.
https://public.blu.livefilestore.com...10E.JPG?psid=1

Photo taken last night directly at the LEDs. Don't recall what voltage I was running them at, but nowhere near max. & they were still very bright.
https://public.blu.livefilestore.com...99E.JPG?psid=1

Had to run the two 250watt 14000K MH Plusrites yesterday while I was completing work on the LED fixture, so here's a tank shot to compare with the LED photo from last week. MH
https://public.blu.livefilestore.com...90E.JPG?psid=1

and the LEDs. Nicer spectrum & more pleasing to the eye to me. Better blend overall & still underdriven. Not too shabby at less than half the power consumption of the Halides.
https://public.blu.livefilestore.com...80e.JPG?psid=1

Very happy with how it's turned out & livestock appears to be adjusting without issues. Female Maroon clownfish spawned a couple days ago, so she's clearly ok with it. Will take some time until I know how the coral fares, but everything looks quite happy after a week under the LEDs. Have 7 Blue & 2 Royal Blues left over from the build, along with miscellaneous wiring, hardware & resistors I didn't use. The fixture easily lights a 4 foot tank, weighs only around 7 pounds & the cost of material is somewhere in the neighbourhood of $600 to $700.

A little over a month now running the fixture. Not completely finished, but I've stained the wood & half attached some of the trim to make it a little nicer to look at. Still need to figure out how to cover the top without adding a bunch of weight & restricting air circulation to the heatsink/fans. Something thin & flexible I can sort of bend into a shallow dome perhaps.

Everything appears to be adjusting nicely to the LEDs, with no apparent issues, other than the green algae. Since this fixture is providing more blue light for a longer period of time, the green stuff is taking it on the chin & tank is looking better every week. All coral including several sps bits continue to grow. Will take more time to get a better idea of the rate, but just the fact that they're doing well is a good sign.

Latest photos. Fixture is dimmed down for morning dawn effect. Things get much brighter when I crank up the voltage.
https://public.blu.livefilestore.com...42e.JPG?psid=1

https://public.blu.livefilestore.com...43e.JPG?psid=1

How are you getting the reflectors and lense installed?

I won't be using optics. Things are looking great without reflectors & lenses. I think the colours blend more effectively without lenses.

Fixture running great since beginning April. Thought an update may be in order. I've added a second power supply allowing me to run each on a different timer to give a simple dawn/dusk scenario. Still no automatic dimming other than that. Added a fourth manual dimmer to allow individual control over each of the 4 different colour LEDs I've used. Two meters provide voltage monitoring through a couple of switches I added. The top voltmeter shows volts for the two left dimmers fed by the 250 watt power supply (Royal Blue & 10000K LEDs on the outer rails). The lower voltmeter monitors the smaller 150 watt power supply (6000K & Blue LEDs on the center rail). By using the DPDT switches I can toggle between monitoring the voltage provided through each of the 4 dimmers. Here's a pic of what it looks like at the moment.

https://public.blu.livefilestore.com...95e.JPG?psid=1

All the 10 watt LEDs should be well 'burned in' by now and the only thing that has failed is one of the heatsink fans. Easy enough to replace since I have a few spares kicking around. Still running without any constant current devices, relying on the dialed down voltage to keep things safe. Intend to do some current measurements to see how things are matched between LEDs, but it's been working so well I wonder why I should bother. If one were going to cook, it surely would have done so by now.

Update I reckon after running the fixture for almost 7 months. LEDs still going strong, no burn outs.

I finally cut the heat sink fan leads off of the LED terminals & wired them separately to the power supplies. A whole lot of cutting, soldering & running more wires to feed 27 fans, but now the 12 volt fans are getting at least 10 volts DC regardless of what I do with the LED dimming controls. The issue of giving the fans a kick start in the morning with my finger due to low voltage delivered to LEDs is now solved. Reliable start of the fans.

https://ojcrhq.blu.livefilestore.com...78e.JPG?psid=1

Note the way the emitters are wired above, with the fan leads soldered in parallel with the LED leads. All the fan leads have been cut & rewired. In the future whenever I replace a fan, I'll keep the connector on as shown on the center LED. Stripped 20 gauge solid strand wire slides into the connector nicely, no soldering.

Coral & other livestock doing well, tank looks good, saving electricity, evaporating less water. Downside I guess is the heaters need to run longer to keep the tank temp up.

Fantastic build man, light looks excellent.

Thanx, it's been running well since last April. Last week I finally did some additional current measurements. Been meaning to do this for some time since the only other time I measured current was before assembly. Constant voltage is not the conventional way of running a LED fixture & doing so has its risks, but I've seen instances of folks cooking their LEDs with constant current drivers as well.

At any rate, the current measurements taken at several different forward voltages revealed that I've really been underdriving the fixture. Highest I've had the voltage is around 9.5 volts which is 0.5 volts above the lowest recommended voltage for the Royal Blue LEDs. That was only for a short burst though & since putting the fixture in service I've kept the voltage at about 7.5 max.

There was a definite difference in current between a Blue & a Royal Blue at 8.5 volts, with the Blue drawing 310 mA & the Royal Blue drawing 500 mA. Both numbers are well below the 1,000 & 900 mA rated current. It took 10 volts to get the Blue up to 500 mA. By comparison, a 10,000K white was only drawing 180mA at 8 volts. Need to keep in mind that the voltage/current curve is not linear & current rises quickly once you get close to the maximum forward voltage. One of the reasons I've kept the voltages fairly low up to now.

Only checked one or two of each colour LED so I need to do more measurements to compare the current difference between LEDs of same colour at the same voltage in order to see how well (or not) balanced things are. After running for months, they have to be 'burned in' & there should be no surprises, but with electronics you never know. They're well cooled with the individual fans now running at 10 volts, so I'm reasonably confident that there should be no major disaster even if one or two burn out & I don't notice for a while.

Even at the 6 to 7 volts I've been running the LEDs at, coral growth was very good, comparable to my previous Halide/T5HO set up. Since taking the current measurements recently, I've bumped up the voltage of each colour to 8.5 and the tank looks great. Quite a bit brighter, especially the whites, so I'll need to keep an eye on things to ensure I'm not burning coral. Looks good so far after several weeks & algae is not getting out of hand either. Could probably run them all at 9 volts, which is recommended minimum forward voltage for all colours except the 10,000K whites (10 volts), but there seems no need to do that based on growth & look of the tank. Besides, that would use more power & probably shorten the life of the LEDs somewhat.

To provide additional flexibility to the fixture with regard to dawn/dusk effect, I've decided to add some SMD5050 RGB strips. During the longer summer days ambient daylight minimizes the effect of the sudden blast of light when the 10 watters kick in, but this time of year it's quite a radical wake up call for the livestock in a darkened room.

I scored a 5 meter reel of waterproof RGB LED strip lighting online complete with 44 key IR remote control & 12 volt DC 5 amp power supply for about $35. Had to wait a month to get it, but can't complain for free shipping & no brokerage fee or customs hit. Had an 8 foot length of the thin aluminum angle left from the 10 watt rail build, so I cut that into 2 sections & stuck the RGB strips to them. The aluminum angle will be attached to the existing center rail of my fixture using stainless #4 screws. I've threaded the holes so should be a slick & easy addition. I'll need to disconnect the fixture & take it down though, so I can drill & tap matching holes into the center rail.

Photo of the strips mounted to the alu angle. They come with a 3M sticky backing which holds well, but a zip tie at each end to support the connectors adds a bit of security.
https://ojcrhq.blu.livefilestore.com...44e.JPG?psid=1

Opposite end. The RGB control box with IR receiver attaches to the connector. Power supply plugs into the other end of the control box. Plug & play with more colour choices, dimming, flash modes than I'll ever need.
https://ojcrhq.blu.livefilestore.com...50e.JPG?psid=1

I loosely laid the two strips above the tank the other day to see how it looked & they put out quite a bit of light. The 5 meter reel of 5050 LEDs consumes 36 watts, there are 60 LEDs per meter providing 780-900 lumens/meter. Each of the strips I cut off the reel is just over a meter long (approx. 41 inches). This gives me 63 LEDs/strip, for a total of 126 for dawn dusk/tweaking or night lighting. Good thing they can be dimmed with the 44 key remote. One of the timed power bars I use for the 10 watt LEDs has the alternate day/night receptacles, so the plan is to plug the strip light power supply into one of the night jobs. Still not as good as having a controller to turn the strips off at some point during the night when I'm not home, but better than nothing I guess. When I'm away I may just set them up to be fully dimmed red all night.

Hey Mike,

I scored a couple of those same ones and am planning on using them above my kitchen cabinets.

Nice way to use them on the tank!

Indeed, uses for LED strip lights are almost limitless. I considered using the whole reel as Xmas lighting on a spruce tree in my front yard, but found that I probably need more than 5 meters for that! So I ended up using the crappy tire LED strings I bought a few years ago. Many of those are beginning to burn out already though & they don't have the flashing/dimming options, so I'm thinking of ordering a few reels for next year.

i was trying to understand the whole circuitry from all the post here.
Sorry i have few quick questions as i trying to follow these post and make sure i get the correct understanding
In the end, you didn't have any resistor in series with each LED, right?
The whole circuitry is just the 12V power go into the dimmer and from dimmer go to the LED. Please correct me if i am wrong.

You are absolutely correct. The two 12 VDC power supplies have a limited range of adjustment via a small potentiometer next to the wire terminals. The adjustment range is from about 10 volts to 13 volts. Downstream of the power supplies are the manual dimmers which provide further control & enable me to dim all the way to off.

The LEDs are all hooked up in parallel, no series chains whatsoever. If one of the LEDs were to burn out, the remainder on that dimming circuit would likely run at a slightly higher current which poses a certain risk if I don't notice for a while. I mitigate that risk by having the manual dimmers adjusted to 8.5 VDC, which is 1/2 volt below the recommended minimum forward voltage of my 455nm Royal Blue LEDs (spec for them says Vf should be 9 to 10 volts). So in essence, I am slightly underdriving the Royal Blue LEDs. The whites, 10000K & 6000K as well as the 470nm blues can handle a higher Vf (up to 12 VDC) so they are underdriven even more. In addition, each LED has its own fan for cooling, which adds to the safety factor with respect to burn outs.

I opened up a couple of the dimmers to see what makes them tick since there is little info on them other than the rated input/output. Some of the vendors selling them on eBay talk about them being pwm and/or constant current capable but it sure would be nice to confirm how they really work. Aside from the potentiometer, the dimmer consists of solid state circuitry including what looks like a MOSFET transistor, so they do have some complexity. Despite the low price, the soldering & assembly are very good quality.

Thansk for your explanation.
Te 12V DC power supply, the potintiometer you mention , is it the the plastic which have philips screw head?
my dimmer just arrived yesterday. I have yet to open up to inspec what is inside , but it felt like almost nothing and very light wieght. I have LED which spec at 10watts(running at 10V, 1A current). Theoretically should able to handle up to 8 LED per dimmer base on the label stated there 8A. For safety reason, i might just want to keep 6-7 LED per dimmer.

On both my power supplies the adjustment potentiometer is as you describe, located next to the power supply power "ON" indicator LED. If you look at the photo on post #46 closely, you should be able to see it on the left of the power supply front panel. It's the only adjustment that is accessible from the outside of the power supply.

Definitely a good idea to keep the number of LEDs per dimmer below 8 as you plan to do. Having said that, the dimmer controlling my 10000K LEDs is doing fine with 10 of them hooked up. Of course I don't run them at full voltage/current, but it reminds me that it might be a good idea to add one more dimmer! Seems to me when I first ran the fixture one of the dimmers had both the 10000K & 6000K on it, meaning a total of 14 LEDs plus the cooling fans! No issues, but I don't know what I was thinking & certainly wouldn't recommend that, even though I had the voltage down at 4 to 5 volts.

A few additional photos showing the 5050 SMD LED RGB strip lighting I recently added to the fixture. Since I don't have a controller running the 10 watt chips, I'm using the RGB strips selected to blue on a timer to provide a crude dawn/dusk effect. I suppose I could have simply purchased a straight blue strip instead of RGB, but the cost difference is minor & it's interesting to play with the different colour combos possible with the IR remote control pad & the RGB strip.

Close up of the strips mounted along the center rail of 10 watt emitters. I simply drilled/threaded the center rail alumiunum angle in 4 locations & used small stainless steel screws to attach the angle holding the LED strips.
https://ojcrhq.blu.livefilestore.com...51e.JPG?psid=1

This shows a bit more of the fixture with the blue LEDs shining.
https://ojcrhq.blu.livefilestore.com...61e.JPG?psid=1

Now for some shots over the tank with different colours. Blue, red, violet/purple and white (using all 3 colours). I've left out the green since it's not a colour one would normally use on it's own over a marine tank. Photos are all with respective LEDs at full power. They can be dimmed down to near zero with the 44 key remote control.
https://ojcrhq.blu.livefilestore.com...71e.JPG?psid=1

https://ojcrhq.blu.livefilestore.com...69e.JPG?psid=1

https://ojcrhq.blu.livefilestore.com...73e.JPG?psid=1

https://ojcrhq.blu.livefilestore.com...72e.JPG?psid=1

As you can see the 'white' shot lights up the tank fairly well with the 2 rows of 5050 SMD LEDs at full brightness. Each row sports 63 LEDs in segments of 3 for a total of 126 LEDs. I have 174 LEDs left on the spool to use on another project. Someone with a FOWLR could easily build a suitable fixture using additional rows of these. Could even work for a tank with softies & LPS. You'd have to mount them fairly low & pack a bunch of rows together, but the stips are available with various levels of water proofing, so that shouldn't be an issue. There are brighter 5630 SMD strips available, as well as less bright 3528 SMD strips. A fairly simple diy to either build a full fixture, supplement existing lights or dawn/dusk effect which is what I use them for.

Just to comment, I brought in 4 x 50cm strips of the 5630 Samsung LEDS in cool white and they are very very bright. They came mounted on a thin aluminum strip with a surrounding aluminum mount and after running for 5 minutes you would be burned by the aluminum strip. The surrounding mount is still fairly cool. Mounted to a proper heat sink, these would shed a lot of light! Haven't seen them in any colours or RGB yet.

Do you design custom led headlights. I need them and ready to spend good money on them

Still waiting for your reply

Sorry no, I don't custom design LED headlights & am not in the LED light manufacturing business. If I was, I think I'd be breaking forum rules here & jeopardizing my membership. This is a DIY project for myself only & information to benefit others that may wish to embark on their own project.

I've actually been looking for LED car headlights myself & haven't found too much. Not sure they are even legal if retrofitted in certain jurisdictions. Most car/truck headlight retrofits seem to be HID & Xenon, not LED.

Mike,

Thanks for sharing you LED build.

I'm also in the process of designing me LED setup on paper. I will also be using the 10W LED's.......prob looking at 24 LED's for my 120 gallon reef tank. I will be using the Mean Well drivers instead of 12VDC 20A power supply with dimmers. I will also be just about finished building my programmable 4 channel light controller based on the Arduino PLC. The controller can be programmed to dim the lights throughout the day via PWM. The Mean Well drivers can be dimmed via PWM.

Did you design you setup with a 12VDC for simplicity? Dimming the lights is done manually using the dimmers?

Once again, thanks for sharing!

Your plans sound interesting & it should be a great set up with the controller etc. A build thread to show your progress would be great. Not sure what your plans are with respect to livestock, but you might want to add a few more LED arrays for a 120. As you can see, my 77 uses 27 LEDs plus two strips of SMD5050 LEDs.

As far as my decision to go with constant voltage 12 VDC power supply, simplicity comes into play a bit, but cost was another consideration. One of the things I'd like to do in the future is put up a solar panel array for my home & this could potentially provide most if not all the power for my LEDs. Most photovoltaic systems are designed to produce 12 or 24 volts DC to charge batteries, so I could potentially run my LEDs off the solar array or battery bank. Need to keep in mind that the charging voltage will be higher than 12 volts to charge the batteries, so resistors in series with the LEDs would be needed. This is one of the reasons I chose 10 watt LEDs as opposed to the larger chips. Most 10 watters have a Vf of between 9 to 12 volts, so that keeps things really simple & cuts down on the amount of voltage conversion (drivers & other hardware) to run the LEDs. I see now there are a few 20 watt multi chips LEDs that have a Vf in that range. For now I like the idea of only having 2 power supplies. The number of electrical outlets I have available for my current set up would mean I'd need a few more power bars to run multiple Meanwell or other constant current drivers. I already have enough of a wiring rat's nest around my tank & more power bars to run multiple drivers are just not an option at the moment.

With respect to dimming, I like it simple there for sure. My dimmers are manual and I haven't touched them since setting the Vf at 8.5 volts for all the LEDs. I use digital timer power bars to bring the lights on line in a staggered cycle to provide a crude dawn/dusk effect. The RGB SMD5050 LEDs help in that regard as well. Less to go wrong, no programming or controller required and for my livestock, not much of a change from the blast of light they used to get from my old MH/T5HO rig.

For a larger future build, I might go a bit more sophisticated with the dimming, maybe. I'll certainly consider using larger, fewer multichips mounted higher up with optics. This would also cut down on the number of drivers, fans, wiring, etc required. By the time I get around to that build, I'm sure the price will have dropped even more on those, better spectrum & other innovations will be available. If I were to rebuild using the 10 watt chips, I might arrange them a tad closer together, like 4 inches on center rather than 4 & 1/2. Maybe even 3 inches. That would allow more LEDs & additional colours to be packed into the same area. I see there are now 10 watt chips available with blue & white on the same chip. Might also consider getting the larger heatsinks for them that don't require a fan. This seems to be the weak link with my build at the moment. I've replaced 3 of the fans to date & a few more are showing signs of weakness. A positive side to this issue is that none of the LEDs have burned out despite some of them running for hours with a stalled fan with no apparent ill effects. It may well be that even these heatsinks don't really need the fan to sufficiently cool a 10 watt LED. The open design with aluminum rails may have something to do with that.

Best of luck with your project, hoping to see how that goes.

Tomorrow will be the 1 year mark running this DIY 10 watt multi-chip fixture. It's been working great, no LED burnouts despite the fact that a few of the fans failed and the LEDs are basically no name cheapies. I have replacement fans so not a problem there, but I would probably build it a little differently next time around. There are now slightly larger heatsinks available for 10 watt multi chips that supposedly cool sufficiently without a fan directly attached. I'll probably order a few of them to check it out. I think if I built a top on the fixture and added a couple of larger fans to move air through that, it may work without all the individual mini fans. I have something in mind along the lines of a semicircular piece of wood at each end, then adding thin slats across the top with a slight space between each. This will cover the top nicely while allowing air circulation similar to the open top configuration at present.

Livestock is happy, coral growing & my BTAs have never looked better. In fact they are taking over the tank. I'm still slightly underdriving most of the LEDs, so they should continue to plug away for another year or two no problem. The fixture is likely nearing the point where it will have paid for itself in power savings & not having to buy replacement halides and T5HO lamps. Starting to get the itch for another build though, this time with larger, fewer multi chips. Anyone contemplating a DIY LED fixture should at least consider these multi chips rather than the more common builds using 3 watt Crees etc. They may not be quite as efficient as the Crees or other big name brands, but the price is right & they work fine. They also now come in multi colour arrays on the same chip. Fewer LEDs can be used meaning less wiring & soldering.

https://ojcrhq.blu.livefilestore.com...LED.jpg?psid=1

Hey Mike. I'm still wondering if I shouldn't have gone this way too. I chickened out and went with what I kinda knew already. I think if I get a frag tank running in my basement I might try and go this route and pick your brain again. If you get to making another, definitely log your progress, I'd love watch it get built. :)

I would hardly call what you're doing with the 'Jarduino' build chickening out. More like going all out with controller, programming etc. I've come to appreciate the simpler things these days, without so much computing. It's great to have the many features a controller or controlled LED fixture provides, but the results I'm having with a a few timers running the lights is working for me at the moment.

I continue to watch builds like yours with interest & may embark on something similar down the road, with programmable features. Folks like you are paving the way!

Udate
 

This coming April will be the 2 year mark since I've put this fixture into service. I'm finally preparing a proper top for the thing. All the LEDs are still going strong but the 27 heatsink fans are becoming a nuisance. They are cheap & I suppose I should have expected the odd failure but it's starting to get old with 5 or 6 failures & many of them are getting a tad noisy. Time for a redesign in that regard.

Larger heatsinks that are supposed to provide adequate cooling of the 10 watt multi chip LEDs without a fan have started showing up on eBay so I ordered a batch of 10. They came in recently & I've redone the center rail of 9 LEDs with them. They come drilled/tapped complete with screws to mount the 10 watt multi-chips. Instead of using angle aluminum I opted for a piece of U-channel I had laying around from my old MH/T5HO Frankenfixture. Drilled a single hole in the back of each heatsink, tapped it & screw mounted with a blob of heatsink compound, making the U-channel an efficient contributor to the cooling process.

https://ojcrhq.dm1.livefilestore.com...01e.JPG?psid=1

Running for about a week now & so far so good. Vewy, vewy quiet! The U-channel gets quite warm but not hot enough to burn fingertips. I had to remount the SMD5050 strips used for supplemental lighting because they'd been attached to the aluminum angle of the original rail. No biggie, but they're a bit higher now, attached to the wood braces of the fixture frame. The new rail weighs only slightly more than the original.

For the cover, I've cut two arc-shaped end pieces out of the same material used for the frame & my idea is to span these with strips of wood, effectively hiding the mess of wiring. Spaces between the wood will allow warm air to vent and I plan to add a couple of larger fans to boost circulation. I have 20 more of the large heatsinks on order to replace the outer rails, so I'm thinking additional flow to keep things cooler will be required.

I've laid some thin pine slats left over from another project on to the end arcs, noting that they sag in the middle due to the 4 foot span. Might have to rethink that & go with very thin plywood that I can bend to shape over the end pieces. Will need to add slots or holes to ventilate. Or I could go with some corner molding, which might hold it's shape a bit better, but not sure I'd like the look of that. Whatever I decide, I'd like to keep it as lightweight as possible. If anyone has ideas, I'd be glad to hear them. I'd like to stick to wood as a material. A couple of coats of finish & the thing should look quite pleasing to the eye.

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Do have suggestions but would love to come see your setup sometime Mike. I also liked those heatsinks so much I bought three myself today. I have 3 10w chips sitting doing nothing so I figure I'll do something with them now.

Hey Mike, can you just cut 2 matching arc shaped pieces of 1/2" ply or something and just stick them in 1/3 of the way from each end, effectively cutting the span of those strips to 16"?

My main display's DIY LED unit using 10w emitters has a big enough Al heatsink that it uses NO fans and stays barely warm to the touch. Should consider upping the heatsink size/mass to dissipate the heat.

Thanks for the suggestion. I have considered an additional support near the center of the fixture, but there's just too much stuff in the way, wiring, terminal strips etc.

I have no idea what an "Al heatsink" is or how many emitters you have attached to it, what your spacing is, so more details as to size, weight etc. would help. I'm trying to keep the weight of the fixture reasonable, so not too keen on adding excessive mass. This is the reason I went with the small heatsinks with individual fans in the outset. The fixture hangs by two anchors in the ceiling (I think one is in a stud, but the other is just in drywall), so I'd rather not take the chance on excessive weight causing my fixture to pull loose & fall. The new heatsinks I've used for the center rail seem to be doing the job without fans, so I'm fairly confident that modifying the remaining two rails with the same hardware with a couple of good quality fans to move some air through the fixture should be more than adequate.

More details on your fixture would be a great help. Do you have an update to your LED build thread?

Sure thing. My setup is pretty modest, but yeah, I'd be happy to let you have a look see some time. My schedule is pretty flexible, I'll shoot you my phone # by pm. I'm in the old part of town on Mission Hill, a few blocks southeast of the hospital. I've been planning an upgrade for years, room divider probably similar to what you've done, but not much progress due to other things in life keeping me busy & drawing on my finances.

Mike instead of a center brace, a half moon, maybe a quarter moon shape in the middle will clear all the wiring, terminal blocks etc.

Al is Aluminum. My lights use Aluminum bars connected into a heatsink. Dissipates heat well.

Small, light-weight heatsinks will have more trouble dissipating the heat from 10w emitters so you'll probably have to continue using fans.

Hmm, half moon, that's an idea. Thanks.