BSOD LED build

[BluScrnOdeth]

here is the case and heatsink. waiting on the other parts to show up later this week.

The hole i'm milling is where the PSU goes.


<img src="http://www.aquatic-refuge.com/RandomPics/mill1.jpg" width ="600"/>

<img src="http://www.aquatic-refuge.com/RandomPics/mill2.jpg" width ="600"/>

2 80mm fans (quiet and push a lot of air)

<img src="http://www.aquatic-refuge.com/RandomPics/slimcase1.jpg" width ="600"/>

air hole ports on the right

<img src="http://www.aquatic-refuge.com/RandomPics/slimcase2.jpg" width ="600"/>

<img src="http://www.aquatic-refuge.com/RandomPics/slimcase3.jpg" width ="600"/>

 

[JW65]

That looks VERY NICE! What is the black material that the case with the fans are in made out of? Can't wait to see the rest of the build.

 

[BluScrnOdeth]

It is black acrylic I bought from USPlastics

 

[BluScrnOdeth]

I will be mounting the LEDs tonight and getting everything connected. Just got to make a pitstop at Radio for a couple parts.

I dont know about anyone else, but i use superglue along the edge of the star to hold the LED to the heatsink. I prob should just use some thermal epoxy, but in the event that a LED burns out i wanted to be able to remove it. I thought about using screws, thats a lot of holes to drill and tap.

 

[T Diddy]

looks good...anxious to see the finished product

 

[widmer]

I dont know about anyone else, but i use superglue along the edge of the star to hold the LED to the heatsink. I prob should just use some thermal epoxy, but in the event that a LED burns out i wanted to be able to remove it. I thought about using screws, thats a lot of holes to drill and tap.

I would probably not recommend the superglue idea for a couple of reasons:

1. There's no saying how well the superglue will hold after being subjected to continual heat-cool cycles. For instance, it could release partway at some point, allowing the star to separate from the heatsink by just a tiny bit, but enough to cause it to no longer have much contact and end up frying.

2. Depending on the properties of the superglue it could potentially seep into beneath the star via capillary action or similar mechanism, and end up creating an insulating layer.

3. Thermal epoxy certainly isn't the unbreakable hold that it's advertised to be. Plenty of people on these boards have reported prying the stars off that were thermal epoxied on, no problem.

 

[BluScrnOdeth]

Thats good to know widmer. I have been using superglue (after i let it harden) for a couple months now and havent had any issues. I should have mentioned that i use the gel type and not the runny watery type. I havent notied any superglue to get under if i let it dry completely before i let it run, or yeah, it will solidify (become a little more runny) and get under the tip of the LED. Otherwise, thus far, with letting it completely dry for 1-2hrs, it hasnt gotten under any surface that is touching the heatsink.

But i do think next time i am going to purchase some thermal epoxy just so that the whole applying process is easier.

 

[BluScrnOdeth]

Figured i would throw out some rough specs as far as the size. This one is close to (dont have exact measurements in my head atm) 18.5x8.75x3.75". I have 2 more to build and i think i can get it as slim as 3.25-3.5" but the width and length will remain the same. This has no external power source, its all internal. Just a power cord that comes out the back.

I want to build a PWM for it, but thats something I'll be investigating shortly. Not sure what effects that a PWM inline would have on a PSU. This is not a meanwell build. It is a resistor/fuse build.

My other unit i built is a bit thicker as it was just a project box and this was the rating for them (this new unit will be the same power specs).Current stays close to 900 +-5% for my CW and 800mA for my RB +-5%. I reduced the PSU to 46.5V since i didnt use variable resistors (didnt think about that when i bought them). I needed the resistors even though the PSU is adjustable because i have 2 80mm fans running off it as well.

 

[BluScrnOdeth]

Since i had nothing to do other than debate about how CREE LEDs are not much more expensive than alternatives and save you a lot of money in the long run (on another website...) (when comparing new lights, energy savings, no bulb replacements, etc) It will pay for itself over the next 5 years or sooner.

Here is a pic, i got the LEDs glued down, optics glued on, and all soldered together. I have to get the barrier strips mounted and the holes drilled that hold everything together. So i will be finishing this unit up tomorrow. I'm going to dim the whites a tad, i want a bluer' look than the MH bright white. Also need to get some more shrink tube, cant find what i thought i had left so i just electrical taped it for the time being.

Drill 8 holes, tap tap 4 of them, assemble the whole thing, should be easy.

<IMG src="http://www.aquatic-refuge.com/RandomPics/ledsetup.jpg" width="600">

This unit is smaller than my other, but same LED specs, i'm getting 360PAR 24" deep water.

 

[BluScrnOdeth]

got my LED unit done today. Now to work more on the tank.

<img src="http://www.aquatic-refuge.com/RandomPics/led1.jpg" width="600">

<img src="http://www.aquatic-refuge.com/RandomPics/led4.jpg" width="600">

<img src="http://www.aquatic-refuge.com/RandomPics/led5.jpg" width="600">

<img src="http://www.aquatic-refuge.com/RandomPics/led6.jpg" width="600">

<img src="http://www.aquatic-refuge.com/RandomPics/led7.jpg" width="600">

<img src="http://www.aquatic-refuge.com/RandomPics/led8.jpg" width="600">

 

[widmer]

Looking sharp. What exactly are you using to drive the LEDs? You're not directly attaching them to the PSU are you?

 

[BluScrnOdeth]

No. The leds are running at 800RB 900mA CW. They have a 1aa fuse and a 2.5ohm 5watt resistor inline.

 

[widmer]

Sounds great. Being able to run the LEDs without a specific driver marketed for LEDs is overlooked by a lot of people I think. When done properly, using a power supply with fused strings can be the least expensive and most efficient way of running LEDs...

 

[BluScrnOdeth]

Yeah. Buying drivers for 128 leds when I can buy 4 PSU's for half the price... pretty much a no brainier for me. But I understand why they buy them. But I also keep them fairly under their limits though.

 

[BluScrnOdeth]

Figured i would post some pics of the coral under the new lights

<img src="http://www.aquatic-refuge.com/RandomPics/IMG_20110422_213421.jpg" width="600">

<img src="http://www.aquatic-refuge.com/RandomPics/IMG_20110422_213430.jpg" width="600">

For some reason my clown hosted the Duncans...
<img src="http://www.aquatic-refuge.com/RandomPics/IMG_20110422_213502.jpg" width="600">

<img src="http://www.aquatic-refuge.com/RandomPics/IMG_20110422_213547.jpg" width="600">

 

[BluScrnOdeth]

Sounds great. Being able to run the LEDs without a specific driver marketed for LEDs is overlooked by a lot of people I think. When done properly, using a power supply with fused strings can be the least expensive and most efficient way of running LEDs...

I wasnt going to use the resistors because the PSU's are adjustable. But i wasnt sure how well that would work on my fans since they are 48V. Running the fans at 44V or whatever needed to reduce the LEDs i think would be an issue. I already dropped the voltage down to 46.5V and they havent had any issues. The PSU does get a bit warm, but the 2 80mm fans seem to be doing a great job at getting the heat out of there.

 

[widmer]

I'm not sure what variety of fan you are using, but from my experience the PC case fans for instance that are designed to run off 12 volts seem to be stable and reliable at least down to 8 volts. If it is the same style fan, I would imagine that 44v would be no problem. So if you want to save a few watts and some heat you could always give that a try and just monitor for a while when the fixture turns on to see if the fan kicks in...

 

[ebola]

Looks good!

 

[BluScrnOdeth]

I'm not sure what variety of fan you are using, but from my experience the PC case fans for instance that are designed to run off 12 volts seem to be stable and reliable at least down to 8 volts. If it is the same style fan, I would imagine that 44v would be no problem. So if you want to save a few watts and some heat you could always give that a try and just monitor for a while when the fixture turns on to see if the fan kicks in...

Not sure if mine are PC fans. But they are 24v fans in series. So I am thinking that I could turn them down a little as the voltage drop would be divided by two. I'll give that a try later tonight.

 

[BluScrnOdeth]

would someone mind helping me find a POT for my system. I want to control the whites and blues independently but I'm not confident that a 5w 10-20k ohm POT is what I'm wanting. I have seen POT's range from 8-$$$.... I did not know they cost so much.

As i think i mentioned earlier that my system is running off a variable 48v AC-DC PSU with a quick blow fuse. The LEDs need to be able to smoothly adjust.

BTW Widmer, i took the resistors off that i had on there before and the PSU was able to adjust down far enough to keep the fans running and make the lights dim enough.