DIY LED Using 10 Watt Arrays

[emerald crab]

I used one 20000k, one 6500k, one 455nm (royal blue) and one470nm (blue). I used 100 mm (4") PVC pipe and yes I did use optics, one 100 mm diameter glass lens f=80mm. I like it better than individual optics. All the bolts used are 6-32. The swivel mounting was supposed to be used for mounting speakers on the wall. I bought that from Walmart 5-6 years ago. I don't remember what I paid for, but it wasn't expensive.

[mike31154]

Originally Posted by emerald crab

I used one 20000k, one 6500k, one 455nm (royal blue) and one470nm (blue). I used 100 mm (4") PVC pipe and yes I did use optics, one 100 mm diameter glass lens f=80mm. I like it better than individual optics. All the bolts used are 6-32. The swivel mounting was supposed to be used for mounting speakers on the wall. I bought that from Walmart 5-6 years ago. I don't remember what I paid for, but it wasn't expensive.

Thanks for the details. The swivel mount is definitely a nice touch. That's quite a mix of colour temperatures in one LED cannon too! I'm beginning to wonder if my approach will blend the colours adequately.

Progress with my build. BC Fasteners & Tools in Vernon was able to get in some #4-40 stainless machine screws allowing me to mount up more LEDs. I've asked them to bring in another 40 of them plus 2 M2 taps. Not able to use the same holes for mounting as with the M2 nylon screws, but it works. The#4 screws butt up against the curves at the corners of the LED base & the larger head clamps down nicely on it. The #4 tap is larger & more robust than the M2. This time though, I dipped the tap into some diesel fuel to make cutting easier. Diesel is the closest thing I had on hand to kerosene, which is apparently the preferred tap lube for aluminum. Here's a photo showing two arrays, one mounted with the nylon M2 screws & one with the stainless #4s. Several LEDs are mounted using both since I wasn't able to extract the broken pieces of the M2 tap out of the holes.



I've reconfigured the rail to hold 9 LEDs in total. The plan is to start with 5 of the 10,000K LEDs & 4 of the Royal Blue LEDs. Would like additional colours, just not sure how to fit them in at the moment. Perhaps a third rail or some MR16 bulbs. Spacing between the LEDs is now at 4 & 1/2 inches on center. This leaves about 6 inches from the center of the first & last LEDs to the ends of the rail. Two rails to start with, so a total of 19 LEDs for almost 200 watts. The 250 watt power supply will handle that with a few watts to spare. Hoping this will adequately replace my current ghetto DIY 2xT5/2x250 watt Halide rig. Total wattage there is close to 600 watts, I'm overdriving the 4 foot T5 tubes. The 10,000K T5s run morning & evening, with the 14,000K Plusrite Halides coming on in sequence during the midday period. BTAs, LPS, softies & a couple of SPS frags all looking healthy & showing steady growth under the current lighting scheme. Still need to figure out how I'm going to time the LEDs.

Things will be a lot more open with two rails of LEDs replacing this monstrosity.



Have to wait until I hang the rail to see how the LED spacing works as far as blending the 10,000K & Royal Blues without optics. Specs for these LEDs generally quote a viewing angle between 120 & 140 degrees. Intensity will surely be less at the perimeter as directly underneath each array. Will be a matter of adjusting height & spacing between rails to see what works. Further reconfiguration/adjustment is always an option. Still need to complete wiring, measure current for each LED to determine what I need resistance wise for each to run them at the proper level. 5 more heatsinks in the mail & I'll need a few more to get the 9 per rail that I'm shooting for. Couple of spares are probably a good thing too.

[emerald crab]

How the light is gonna blend is a matter of optics used. You might want to bring them closer and install a few more LEDs.
I did play with some small heatsinks, similar with yours. They need 12V to stay cool and at 12V they are a kind of noisy. If you want to see those contraptions I can take some pics.

[mike31154]

Originally Posted by emerald crab

How the light is gonna blend is a matter of optics used. You might want to bring them closer and install a few more LEDs.
I did play with some small heatsinks, similar with yours. They need 12V to stay cool and at 12V they are a kind of noisy. If you want to see those contraptions I can take some pics.

A build thread on your light would probably generate a fair bit of interest. More info on your optics & where you got the lens would be useful. How is the lens attached? Do you have more of these lights or just the one & what area are you lighting up with it, tank size etc.?

I'd like to try the rail in the current configuration without optics and see how the colours blend. Looking at the photos of SeaHorse Fanatic's build, the light seems to blend quite well. Unfortunately, other than the number/type of LEDs & PAR readings, details of his build are scant & I have no idea how his LEDs are spaced or if he's using optics. The optics I have for these at the moment are thick glass & quite heavy. Not sure how I would mount them so I'll play with height of the rail above water to see how that works first. I recall reading that any optic, glass or acrylic is going to filter out a certain amount of light. So it's a bit of a trade off between the need to focus & the desire to get maximum lumens out of each LED without filtering.

Not sure what heatsinks you played with, but the ones I have are designed specifically for these LEDs. Running the fans at a lower speed with lower voltage may well shorten the life of the LEDs. If I find the heatsinks get too hot, I may have to cut the fan leads & run them separately at full 12 volts. I only ran each fan briefly to make sure they all work & didn't find them that noisy, barely audible actually. Currently I have fans cooling the ends of my overdriven T5 tubes & I can definetely hear them. I've lived with that sound for years now, so the LED fans will not make a difference in that regard.

Thanks for the continued input regarding your experience with the 10 watt LEDs. And yes, more photos would be cool.

[emerald crab]

The heatsinks you have are videocard sinks and they sell around $2-3 on e-bay. In one of the first pics you posted they even had the plastic clips used to fasten them to the pc board. If you bought them as specifically designed for led you probably overpaid. When you run just one the noise is not a big issue, but when you run 12-24 that's a different story. When I played with the VGA heatsinks I used same kind of glass lens that you use and I liked them. I don't want to hijack your thread, but I'll post some pics showing the lens mounting.

[emerald crab]

Here are the pics of the optic system used with VGA heatsinks. 1.5" ABS coupling, 2 rings cut out of a 1.5" ABS pipe, one 44mm glass lens and two #4 screws (stainless) to attach the heatsink to the optics.

[mike31154]

Originally Posted by emerald crab

Here are the pics of the optic system used with VGA heatsinks. 1.5" ABS coupling, 2 rings cut out of a 1.5" ABS pipe, one 44mm glass lens and two #4 screws (stainless) to attach the heatsink to the optics.

Thanks for the pics, good info. Price I paid for the heatsinks is about what you paid as well, I don't think I've overpaid. Good to know what else they are used for. I assumed they were specifically designed for the 10 watt LEDs since the eBay sellers I've purchased the LEDs from often list the heatsinks as well and the item description says they're designed for them. I reckon in the interest of economy in manufacturing, many heatsinks are used for different applications, provided the specs meet the required cooling capability and have the necessary footprint & mounting options.

[mike31154]

Not much in the way of progress with the build, but I have been scoring a few more parts that I need. While in Kelowna the other day getting more wire at Princess Auto, I found out about a great electronics outlet not far from there, Interior Electronics. Eureka, a shop full of resistors, capacitors, voltage regulators, hard to find connectors, it was like being in a candy store as a kid. I picked up a few 5watt & 2 watt resistors ranging from 1.5 to 3.3 ohms and a breadboard. This will allow me to run each LED chip with the different resistances to determine what value of resistor I'll need to limit the current to the rated spec. Might be a tedious process & I'll need a resistor in series with the power supply for each LED. Also not the most elegant solution by today's standards with LEDs, but simple & effective. A good thing about doing it this way is that failure of one resistor isn't going to take out any other LEDs. About the only thing that will take out multiple LEDs would be an overvoltage fault of the 12 VDC power supply & I'm banking on that being very unlikely.

I used the breadboard with resistors yesterday to run 2 whites & 3 blues at once. Worked very well & the fans were nowhere near as audible as the four I'm using on my overdriven T5 tubes. In theory the 5 LEDs should have been using 50 watts, but if I recall correctly the wattmeter was showing less than that, so I assume they were being underdriven. Still very bright though & I think the 4 & 1/2 inch spacing between them should work fine without optics if I hang them at the proper height.

[mike31154]

For the benefit of those wondering what the H a breadboard has to do with electronics....



Interior Electronics also had some fine little project boxes. What I'm thinking of doing is mounting several of these on each rail with a terminal block & resistors inside to keep things tidy & relatively moisture proof.

[eli@fijireefrock.com]

I skimmed through this tread a little fast excuse me if this question already have an answer
As I am planning to do a 20W led setup for a couple of my tanks similar to what you are doing but 1st I would like to know how good are these fans at keeping these LED cool as I am planing on running then at full power.
By the way good thread on this build.