DIY LED Using 10 Watt Arrays

[mike31154]

Originally Posted by Aughskel

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.

[byee]

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!

[mike31154]

Originally Posted by byee

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.

[mike31154]

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.

[daplatapus]

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.

[mike31154]

Originally Posted by daplatapus

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!

[mike31154]

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.



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.