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-   -   DIY LEDs - The write-up (http://www.reefcentral.com/forums/showthread.php?t=1587273)

Soundwave 02/28/2009 11:16 AM

DIY LEDs - The write-up
 
Many of you have seen my preview. This is the full instruction sheet. I hope it's clear enough but feel free to ask any questions. I will try to respond as soon as possible.

Enjoy!


What you will need:

24 Cree White LEDs mounted on star boards - ~$173.00 from www.LEDsupply.com
24 Royal Blue LEDs mounted on star boards - ~$173.00 from www.LEDsupply.com
4 700mA wired buckpucks (3023-D-N-700) ~$60.00 from www.LEDsupply.com
4 1000mA wired buckpucks (3023-D-N-1000) ~$60.00 from www.LEDsupply.com
Heatsinks – more specifics on this later ~$60.00 from www.heatsinkusa.com
Power supplies – more specifics on this later ~45.00 from www.mpja.com
Arctic Alumina thermal epoxy ~$13.00 – find this in a local computer parts store or eBay
Fans for cooling ~$20.00 – find this in a local computer parts store or eBay
Aluminum project box from Radio Shack ~$3.99
Aluminum stock
Drill and tap set
Stainless machine screws – I used #6-32
16 gauge wire
Precision electronics soldering iron and solder

DISCLAIMER: This project involves both low voltage DC current and high voltage AC current. Risk of electric shock should be obvious and if you are not comfortable with basic electronics wiring, leave this to someone more experienced. As with any project like this, mileage will vary.

Feel free to make any changes or improvements to this design. My main focus is to provide you with instructions on wiring and all the parts needed for a lighting fixture that can save you tons of money and provide just as much light as halides.

I claim that this saves money. Why is that? To begin with, LEDs last for 50,000 hours. After that, they drop about 30% in brightness. How many times would you need to replace halide or PC bulbs in 50,000 hours of burn time? Also, power consumption is far less than even PC lighting for the output.

Getting Started

I have a 75 gallon tank, therefore, I needed a light fixture of 48” in length. I found some 1” angle aluminum in 4’ sections at my local hardware store. I picked up two of them along with 3’ of 1” square aluminum tube. The heatsinks that I used were 12”x8.5”. I cut the square tubing to 8.5” lengths and screwed them to each end of the aluminum angle and to the middle for further support.

NOTE* - The heatsinks can be purchased in varying lengths. Check out www.heatsinkusa.com for sizing.

The heatsinks were easily attached by drilling through and tapping them to allow for the stainless machine screws to securely attach the heatsink to the aluminum frame.

http://i155.photobucket.com/albums/s...DSC04830-1.jpg

Mounting the LEDs

I studied the array of the Solaris fixtures and saw that the LEDs were in an alternating blue/white pattern. This seemed like a winning combination so I did just that. Each buckpuck can safely handle 6 LEDs. This is where I got my array of 24 LEDs in each array VS the 25 in each Solaris array. (6x4=24) I arranged the LEDs in a crisscross pattern as shown.

To attach the LEDs to the heatsink, use the Arctic Alumina heatsink epoxy. As the packaging states, the bond is PERMANENT so make sure you have the LEDs aligned before attaching them. It’s best to save the wiring job until the LEDs are mounted and the epoxy has cured.

http://i155.photobucket.com/albums/s...DSC04837-1.jpg

The LEDs need to be arranged so that they can be wired in series. For example, the first LED, closest to the buckpuck driver, needs to have the negative lead facing the buckpuck direction. The positive of that LED needs to be connected to the negative of the next LED and so on until the string of 6 is complete. The positive of the last LED in the string runs back to the buckpuck.

http://i155.photobucket.com/albums/s...DSC04836-1.jpg

Drivers

As I said, I used 8 buckpuck drivers that can be had at www.ledsupply.com. I used the non-dimmable versions because I didn’t care about that feature. The dimmable versions are slightly more expensive but can open up a few features. For example, you can dim each string to fit your needs. This could be helpful in the acclimation process.

http://i155.photobucket.com/albums/s...700_Medium.jpg

This is a fairly simple setup. All of the negative leads from the buckpucks driving the BLUES will be connected and all of the positive leads will be connected. The same goes for the WHITE drivers. Each LED output from the individual buckpucks goes to an individual string of LEDs.

NOTE* - I used 700mA drivers on the BLUE and 1000mA drivers on the WHITE. Dollar General Ad has unique savings like DG digital coupons.

You will need a place to hide the buckpucks. An aluminum project box from Radio Shack worked perfectly for this, keeping with the all aluminum theme. The buckpucks produce no heat and can be thrown in the box indiscriminately if you wish. However, to keep the wiring (which there is a lot of) in order, the buckpucks can be epoxied to the inner walls of the project box. It would be smart to keep the 700mA on one side and the 1000mA on the other.

http://i155.photobucket.com/albums/s...d/DSC04826.jpg

Drill some access holes in the box as you will need to route wiring through them. I made 4 holes in the front, all 3/8” to both run wires through and allow for the wire loom to fit securely inside the hole. On the back, drill whatever size hole you need to run the power and fans. This is where you get to be as creative as you want. I drilled holes, inserted rubber grommets and ran the wires. You can use whatever you want as the control center and make it look like whatever you wish.

http://i155.photobucket.com/albums/s...d/DSC04841.jpg

http://i155.photobucket.com/albums/s...d/DSC04842.jpg

Power

For power, you will need to acquire a 24V power source that can handle the load of the LEDs. I found the perfect power supply at www.mpja.com. It is a 24V 6.5A CNC power supply. You will need one for each type of LED. The BLUES get one and the WHITES get one.

http://i155.photobucket.com/albums/s...sand/16854.jpg

NOTE* - You can use any type of 24V DV power supply you want. Just make sure that the amperage draw from the LEDs does not exceed the amperage available from the power supply. For example, running 4 strings of 6 LEDs being driven at 1000mA is a total draw of 4 amps. Using a 24V 3A power supply, will, in my experience, kill the power supply. The buckpucks can handle up to 32V but only 24 is needed for a string of 6, which is the recommended maximum number of LEDs per string.

The wiring of the power supply is rather simple as well. You will need an AC cord with a ground. If you can find a few old computer power cords, just cut the end off and wire that to the power supply.

NOTE* - ALWAYS TEST your connections before just plugging the cord into the wall!

The output of the power supply is in a simple positive/negative DC fashion. These will run to the respective positive and negative leads on the buckpucks.

Cooling

High power LEDs generate heat. It’s not a ton of heat, but the cooler they run, the longer they last. I found some 120mm fans on ebay and purchased 4 of them. Check the fan noise rating which is listed as DB. The ones I purchased were listed at 20DB. This is barely audible in a silent room. I found that when they arrived, they were larger than I thought. I only used one on each heatsink and the cooling effect is substantial. Without the fans, the heatsinks would reach a feverish forehead feeling. With them, they are cool to the touch after hours of run time.

http://i155.photobucket.com/albums/s...d/DSC04865.jpg

To mount the fans, I used some flat 1/2” wide lengths of aluminum. They were bent to the shape of the heatsink and mounted with the same drilling and tapping method.

NOTE* - Be sure to raise the fan off the heatsink by at least 1/4” to allow for air flow.

http://i155.photobucket.com/albums/s...d/DSC04867.jpg

So, now you’re looking at this and thinking that the fans are 12V and the power supplies are 24V. How does this work? I had the same problem and the fix is simple. Wire them in series. The positive from one fan goes to the positive of the 24V power to the buckpucks. The negative of that fan goes to the positive of the other. That last negative goes back to the negative of the same buckpuck circuit.

The power supplies get warm, as well. I don’t know if they absolutely need cooling, but I happened to have two extra fans. I added them to the box that I mounted the power supplies in.

Optics

I am fully aware that optics will increase the output of LEDs. However, I decided not to use them because they cut down on the spread of the light. In order to use the optics, successfully, you will need to keep the LED arrays closer together and , most likely, need more LEDs to get the desired spread.

Closing

That’s really about it. You can build this exact fixture for about $600 and never have to replace any bulbs. After 11 years or so, the LEDs will lose some of their intensity. But, that’s 11 years down the road. Consider the cost of replacing bulbs in standard MH or PC fixtures over the span of 11 years. This type of lighting pays for itself over time. Your electric bill will thank you, as well.

As always, your mileage will vary. You can make whatever you want and have it look like whatever you want. The important things here are the wiring and cooling. Other than that, the canvas is yours to paint.

I hope this will help those of you interested in LED lighting but don’t want to spend the incredible prices out there for pre-manufactured LED fixtures.

Thank you for reading this and enjoy!

Soundwave 02/28/2009 11:17 AM

More pictures and PAR readings!

http://i155.photobucket.com/albums/s...DSC04847-1.jpg

http://i155.photobucket.com/albums/s...DSC04849-1.jpg

http://i155.photobucket.com/albums/s...d/DSC04878.jpg

http://i155.photobucket.com/albums/s...sand/After.jpg

Jeff 02/28/2009 12:00 PM

Finally! Step by step instructions, parts list, and par reedings in the same thread. Good work!

troylee 02/28/2009 12:30 PM

super sweet man love it very clean to i might add......i have been wanting to do this but my tank is 8ft man it would cost a fourtune to build it because i hate dark spots i would need a full 8ft run but anyways thats my problem once again nice job man.....on that note whats the distance between the two modules you built???? looks like a pretty good gap and you got decent coverage........

hummermaniac88 02/28/2009 12:46 PM

My god, you are a god! Subscribed and book marked!

How big is your tank? I have a 6', might I need 3 rows of light?

dtech 02/28/2009 01:43 PM

Very nice write up, Very good information and I agree with Jeff fa great write up with all the step by step and PAR in one pace. Again very nice. Now I also know a great plan to follow.
Question for you if I put lenses on would the PAR increase enough to keep a clam in a 30" deep tank?

ChknWing 02/28/2009 02:08 PM

Just a quick question has anyone tested a kill a watt or anything on these to measure the difference in power costs versus a comparable MH. By the way that is one sweet setup, thanks for the write up

stugray 02/28/2009 02:41 PM

Soundwave,

Very nice setup! Exactly what I was planning.
If you want help on a dim-able driver, let me know.

One thing I would ask, is have you tried to remove a star from the heatsink after using that epoxy? Do they Pop right off with a screwdriver?

My plan was to use heat sink 'compound' and screw ( instead of glue ) the stars to the heat sink.
It would make future replacements much quicker & easier.

One lesson learned playing with these things: You cannot turn on a constant current driver ( buckpuck ) open circuited, THEN connect it to the LED ;-0 ( that's Xpensive ;-)

Stu

skunkmere 02/28/2009 02:50 PM

hi, great diy, the best in my opinion. isnt that higher par than mh? or equal to.

Robamus 02/28/2009 03:36 PM

Dude, your a ninja. Thats fantastic.

Doahh 02/28/2009 03:44 PM

Quote:

<a href=showthread.php?s=&postid=14503836#post14503836 target=_blank>Originally posted</a> by skunkmere
hi, great diy, the best in my opinion. isnt that higher par than mh? or equal to.
Lower Than...
If it had Optics than it could be about equal to a 400 Watt MH

robert bell 02/28/2009 05:42 PM

are you going to use some sort of lense to protect led's from salt/water??? would a piece of glass cut down on light output?? would it change light angle thru the glass??

ispurlo 02/28/2009 06:57 PM

Could someone explain what optics are and how they could be applied to this build?

Doahh 02/28/2009 07:08 PM

An optic is a Lens...
It would focus more light downwards.
http://www.ledsupply.com/led-optics.php

Curve 02/28/2009 08:52 PM

Wow $608 for a 4' led light fixture. That's amazing. And yes I took the time to add everything up.

barderer 02/28/2009 08:58 PM

Those white bulbs are rated at 6500K. They may have great par but isn't it the wrong spectrum?!?

goofyreefer 02/28/2009 09:40 PM

I'm curious to see/know what the current draw of this light fixture is? Fantastic work though Soundwave....

Canoe 02/28/2009 10:10 PM

So the LEDs are driven with constant current? As in, 100% full time?
I understand that the life of LEDs are generally life extended to double if they're run at a lower current, OR, cycled at a high frequency at a 70% to 80% duty cycle. A simple RC circuit driving a VFET would suffice. Would also be available to act as a dimmer.

At that duty cycle, the human eye will perceive LED light as around 95% as bright as the constantly driven LEDs. However, we're not just doing this to allow us to look at the tank. How would that affect PAR value readings and how does that relate to the energy provided to the reef?

If it is less (although looking good to our eyes), would adding 20% to 30% (or how many?) more LEDs to the fixture correct this, and you've doubled the life of the entire unit. Much more cost effective?

I'm also interested to see a spectrum graph of the resulting fixture, not just an averaged colour temperature. Does the manufacturer provide such graphs of the two types of LEDs?

Add some heat-pipe cooling to remove the heat from the fixture and to larger heat sinks and you remove the fan's energy use and noise. What temperature do the LEDs produce? A DIY heat-pipe populated with de-ionized water can run well if under 95C.

This has me really really interested.

so much for sleeping tonight...

Keith Elliott 02/28/2009 11:04 PM

Canoe: here is a link to the some of the info you are looking for
http://www.ledsupply.com/docs/cree-xre.pdf

Doahh 02/28/2009 11:16 PM

Quote:

<a href=showthread.php?s=&postid=14506149#post14506149 target=_blank>Originally posted</a> by Curve
Wow $608 for a 4' led light fixture. That's amazing. And yes I took the time to add everything up.
$200 for 2 Electronic 250 watt MH Ballasts
$160 for 2 bulbs
$80 for 2 Batwng reflectors


$440 for a MH setup so what's another $160?

Soundwave 02/28/2009 11:17 PM

troylee: The spacing of the modules is 2 feet. I centered them on each side of the 4ft tank.

dtech: The par skyrockets with optics. The problem, as mentioned is that it creates a spotlight effect and more LEDs would be needed to get the coverage, hence, not using them.

ChknWing: I need to get a kill a watt to find the actual usage. By all estimates with the LEDs and their requirements, this whole fixture should be using less than 175 watts while putting out more light than two 175 watt halides.

stugray: I don't want to even try to remove one of the stars. Not until one dies, anyway. The screw method works just fine but you have to be careful that no screw touches the leads and grounds the whole thing out. Also, I can't even imagine drilling and tapping that many holes!

skunkmere: Better than 175 watt halides.

Doahh: See above.

robert bell: I forgot to mention that I am using a sheet of plexi to keep the water away from the fixture... my bad.

barderer: The spectrum doesn't really count with this. There is no red emitted from the LEDs like MH and T5/PCs.

Canoe: I'm not getting that crazy with this. Maybe on the next fixture. The heatsinks stay completely cool with the fans. Also, if this thing lasts 5 years, it has paid for itself.

I hope I answered to all. Thanks for the interest!

Curve 02/28/2009 11:20 PM

That's what I was saying was that $608 is cheap. I have alreay started a shopping list to do a 6' with 100 white and 100 blue leds. You get the led's about 1.25 sheaper each when you buy 100 at a time. I also found some 300 watt led drivers. I want to do that many so I can get an even coverage and good par ratings everywhere.

pmoneyt 02/28/2009 11:42 PM

soundwave would love to talk more on this. i have a 48x24 tank is that lixture too narrow?

hijinks 02/28/2009 11:47 PM

what if you used 10k-12k led white fixtures.. would the par readings go up.. and what about better color.. less yellow

Soundwave 02/28/2009 11:56 PM

Trust me, there is ZERO yellow, hijinks. It looks beautiful.

pmoneyt: This fixture might work just fine but you may want to add another string on each side to make the spread from front to back a little wider. I'm using this on a 75. Throw any questions out there you may have and I'll do my best to answer them.


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