LED build

[evilc66]

Thanks. Just another side question. Those blue LEDs I posed a picture of in this thread, I want to use as moonlights. There are about 60 LEDS on the whole thing, and I only need about 5 or 6 as they are super bright. The adapter for these says it outputs 12V at 500ma, AC. Each led has a resistor jointed to it. What would I need to do to power just 5 or 6?

 

You should be able to run 6 of those LEDs by running 2 groups of 3 in series, with a 100 ohm resistor at the start of each string. Try and find a DC 12v power supply. The AC unit will make the LEDs less bright as the LED is only on for half the time because of the AC waveform.

[snatchbak]

The layout of the LEDs does not look very even, IMO. It looks like the blues should be more spaced out.

[evilc66]

It probably won't look too bad. With this setup not running optics, it should blend fairly well.

[thedoogan]

Got it all wired up and running nicely, it spreads out great. Its giving the most intense shimmer even resting right on the top, almost too much. Hard to look at!. These things are insane bright!. Thanks for all the help everyone. I will get some pics soon.

[Splumph]

You never know what you've done until you've got it running, really is amazing turning it on the first time eh?

[thedoogan]

oh yah, nothing like building something yourself LEDs are amazing, the shimmer is crazy, nice color temp, and the coral came out and opened up better then they ever have within the first 20 minutes. The Gradient patterns from the light spill on the walls looks awsome, and I even have some shimmer on my roof

[evilc66]

Fantastic. What's your guestimation on the actual color temp?

 

Looking forwrd to seeing pictures.

[thedoogan]

Rightnow 15 to 20K really blue and the corals flouresce. It will probly decrease as I raise the whites while the corals adjust.

[thedoogan]

how warm do your LEDS get to the touch? And how do I tell if my heatsink+thermal paste is done correctly and doing its job?

[evilc66]

Touching the dies themselves, they will be quite hot. If you can get your hands on an infrared thermometer, you can check the area around the stars. Place a peice of electrical tape next to the star so you can get a good reading (aluminum reflects the IR light and screws up the reading). I usually don't let the temperature get above 40C/104F. The die temperature will be higher obviously, but with the size of heatsink you have, good clamping pressure, and a little thermal paste, you shouldn't see those kind of temperatures. Your heatsink will barely be warm to the touch.

[thedoogan]

My heatsink is pretty cool, far from warm yet. The dies are just a bit warm to the touch, the blues more than whites. PICTURES!

Took me a couple attempts but I got pretty comfortable with soldering, love it now.

Bubble coral I picked up from a clearance tank. Hopefully I can get him growing nicely. Any tips?

Whites

shotty temp canopy+fan. I have to pick up some case fans and mount them.

All on low. Not so good even placement haha...I got scared. No screws but I was thinking I can always add them in the future by drilling where they are placed now, possible?

blues

whites

whites on low

all

 

 

A video of the dimming. The only potentiometers I found are too large for the voltage so they are SUPER sensitive.need some smaller ones. The whites dont go all the way up in this. The firefish makes a quick exit when the lights go out

 

Video of the shimmer, the crappy camera video doesnt do justice!

 

 

Do I get a banner now ahaha

[evilc66]

Do I get a banner now ahaha

 

Yes, yes you do.

[Splumph]

Very nice.

[evilc66]

If you used thermal epoxy, I wouldn't bother drilling and tapping. Too much risk for damaging the LEDs.

 

What size pots did you end up using? Should have been a 10K if you are using the Buckpucks. The wattage of the pot won't make any difference.

[thedoogan]

I could only find 50k, they are 3 inches long. I did find a smaller one I had lying around and tried it, its much less sesitive to dim. Its hard to get any range with the 50K its almost on/off...you have to do tiny micro turns....

[NanoReefGuy]

Hi the Doogan

 

If the 50K pots your using are logarithmic instead of linear you may go from 0-5K in around 1/10 of a turn.

 

Cheers

NRG

[evilc66]

Hey! He's back. How was Mexico?

[thedoogan]

Hi the Doogan

 

If the 50K pots your using are logarithmic instead of linear you may go from 0-5K in around 1/10 of a turn.

 

Cheers

NRG

 

Nah, they are 50k Linear pots...

[thedoogan]

Im considering doing a DIY for hanging the fixture from the ceiling for easier access to the tank. How would I go about doing this?

[Splumph]

Drill some holes in the sink (small holes) and loop the cable through, I think you can buy the cable and fasteners at home depot. Griplock would be great but that stuffs expensive. I think on my next project I'm gonna get one of these and take the head off, and replace it with the LED array, then you'd be able to clamp it to whatever surface you want.

[thedoogan]

Thats what I was thinking. a set of 2 holes on each end of the sink, make a loop and fasten it (like a triangle shape?) One problem is that the only stud above the tank runs about a foot infront of the tank and runs length wise to the tank, and then the drywall roof meets the wall behind it. I have a lot of those studio lights laying around. problem with them is they cant hold much weight and sink down and loosen after time.

[Splumph]

How heavy is your array? Swag hooks with toggle bolts (or anything with toggle bolts for that matter) should be able to hold it if it's under 15 pounds, even if not anchored into the stud.

[thedoogan]

I would say 8-10 pounds...

[Splumph]

I'd say find a couple of good looking swag hooks and hang it from those then. Just make sure you cover your tank when drilling the holes

[thedoogan]

Nice. I think I will go that route, although I dont think I can hang just the heatsink. There will be way to much light spill. You will be able to see the actual leds and get blinded when around the tank. I think I will mount that wood frame I have it on now.