DIY LEDs - The write-up

[drewread]

Re: DMX on the cheap

Re: DMX on the cheap

Yes, that is an 'inexpensive' DMX controller made for DJs, however, it has no scheduling abilities, and as such really won't help with controlling your tank lighting. It will basically work like a $200 set of trim pots. You could build cool cues to run, but, AFAIK fish don't disco!

<a href=showthread.php?s=&postid=15510674#post15510674 target=_blank>Originally posted</a> by kecked
http://www.behringer.com/EN/Products/LC2412.aspx

Here is a nice DMX control for $200.00

There are ones for around $60.00 that hook to your computer via usb so all of you who want to do the sunrise sunset thing could do it that way.

http://aa.usno.navy.mil/data/

This site give table for sunrise sunset for any location earth and allows you to calculate where the moon is as well. IF you really want to go to the end you can calc sunrise sunset, use red, yellow, orange leds to sim sunrise and sunset and than calc the phase of the moon and use a track of small white leds accross the tank to simulate the moon traveling across the sky and the intensity based on phase.

In addition to the DMX board you'd need to convert the DMX channel/intensity data to a voltage to run the buckpucks. None of this is really hard to do. I do caution you to use a look up table to do the sun rise sunset thing as the equations are a bit difficult to program and a look up table is much easier to program.

Have I done this no. Do I plan to no.

 

[der_wille_zur_macht]

IMHO, a simple, generic microcontroller is a cheap and extremely flexible option for simulating sunrise/sunset.

A $12 stripped-down Arduino (i.e. the RBBB from Modern Device) plus a few discrete components and you can send PWM, 0-5vdc or 0-10vdc signals to LED drivers to simulate sunrise, sunset, moon phases, thunderstorms, whatever you can dream up and program.

Of course, I now have to repeat a slightly modified version of kecked's disclaimer: Have I done this? No. Do I plan to? HECK YES!

 

[drewread]

I also plan on going this route for my 135 gallom aquarium. I'm looking at about 130+ LEDs.

so maybe there are enough of us that we can pool our resources together and come up with a DIYable solution? Is it possible to start a private thread on ths board that we can use for development? And the we can publish a thread once we figure it all out and we have a working solution?

<a href=showthread.php?s=&postid=15511274#post15511274 target=_blank>Originally posted</a> by der_wille_zur_macht
IMHO, a simple, generic microcontroller is a cheap and extremely flexible option for simulating sunrise/sunset.

A $12 stripped-down Arduino (i.e. the RBBB from Modern Device) plus a few discrete components and you can send PWM, 0-5vdc or 0-10vdc signals to LED drivers to simulate sunrise, sunset, moon phases, thunderstorms, whatever you can dream up and program.

Of course, I now have to repeat a slightly modified version of kecked's disclaimer: Have I done this? No. Do I plan to? HECK YES!

 

[der_wille_zur_macht]

Another user on this forum (jener8tionx) has a website dedicated to using an Arduino as a reef controller:

http://reefprojects.com/wiki/Main_Page

Though I don't think they are specifically using it for LED lighting.

That said, setting it up to dim LED lighting should be much simpler than many of the things they've already figured out. I dunno if it'll really justify a ton of effort as far as collaborative development, it'll probably just be a race to see which one of us ends up posting the finished product first.

 

[AndyReef]

I know its not a technical question.

Where is a good place to get secondary optics? Places like LED supply only have those up to 25 degrees, that is a little too focused for me. I am looking for something more like 40 to 60 degrees. Any help would be appreciated.

 

[King of spades]

Update from Soundwave

Update from Soundwave

Hi, I was wondering if Soundwave could update us on his tank and how his corals are growing under the Led lights.
Are the LED lights still working as expected ?
Are the corals still thriving under the LED lights.

I am starting to build my fixture for my 150 gallons tank (72X18X27) and i ordered all of my items.
I am going for 96 Cree (48 white and 48 blue) it's a start anyway and i will adjust the number of LEDs if needed.

So, having an update from Soundwave would be great (with pictures of course).

Thanks.

 

[yupgopotty]

<a href=showthread.php?s=&postid=15512852#post15512852 target=_blank>Originally posted</a> by AndyReef
I know its not a technical question.

Where is a good place to get secondary optics? Places like LED supply only have those up to 25 degrees, that is a little too focused for me. I am looking for something more like 40 to 60 degrees. Any help would be appreciated.

I'm using 40 degree optics that I got in a LED kit from www.rapidled.com. I believe they sell the 40 degree optics individually as well.

 

[Soundwave]

I'll update soon.

 

[TheFishMan65]

I have actually read all 84 pages of this thread - it took a while.

Here is a suggestion that will protect your LEDs and only one or two can go out at a time (rather than a whole string of 6). The dissadvatage is that you need twice as many, but they will last twice as long. Here is the connection diagram.

--+--*--+--*--+--*--+--*--+--*--+--*--+--
...|........|........|........|........|........|........|
--+--*--+--*--+--*--+--*--+--*--+--*--+--

Where * is an LED
+ is a connection
- and | are wires

You run them at half the maximum current (so yes one buck puck is running two stings in parallel). What happens if one stops working. With this set up it is pretty quick to tell which one needs to be replaced. If we have a short then all the current will go through the short and the LED next to it will be out as well. If the LED is open the LED next to it will be twice as bright since it will have all the current, but this is OK since it is only at the maximum current not double.

Note: if you need to test your LEDs you do not have to cut all the wires (I think someone did that up above). Disconnect the LED string from the buck puck (or whatever) and just use 2 AA batteries (or 3 with a resistor) across each LED terminal and see if it lights.

The life is extended becuase the are running much cooler. While I think LEDs will get cheaper and brighter I am not sure that we will see a new (and better source for a while). So the question is whether to make them last 5 years (with maximum current) or 10 years (at rated current).

 

[tonggao]

Does anyone has email address or phone number for Anna Lopez at ETG? I need to buy a bunch of LEDs and like to check with her. Thanks in advance.

 

[sammy113]

Just call ETG. Probably she'll answer. If not, just ask for her

 

[Reef_Matrix29]

TheFishMan65, in response to how you would check for a blown LED if you wire it in series, all you would really need to do is use a AA or AAA battery tester from Radioshack ($1.79) and touch the second pair of contacts on each LED in that string until you find the one that doesn't light up. While it may take you a few extra seconds to do it, you won't have to worry about voltage increases on the subsequent LED's through the parallel wiring schematic you drew up. Just a thought...

 

[Reef_Matrix29]

Here is Anna's email address: anna@etgtech.com

 

[Henryreef]

This is a great thread, I am still reading through and trying to understand, but it has helped me gain the courage to possibly try this on my next tank!

 

[Reef_Matrix29]

That's how I felt when I first started looking into LED lighting and I will be soldering LED's tonight and wiring up the meanwells too! My completion date is scheduled for Saturday evening so I can view the tank all Sunday with the new lights fully functional.

 

[kecked]

update

update

Update on my led and tank.

The Deresa clam is doing extremely well. I have full brightness from the array acheived. Some of my polyps that had faded to brown are now again showing green centers and are growing. My pipeorgan is growing and out on a regular basis. And the best for last.....I still have zero bad algae growth and very little hair algae growth and a lot of coraline growth on what was once bare rock.

This area is 12 blue and 12 white cree q5 no optics on a 29 gallon tank. Next I'm adding 40 degree opitcs to the edge lights to pull in the spill from the leds. I'll let it all sit for a while and then add back the rest of the optics to get the 250w mh brightness.

Last, I turned off all of my fans. The heat sink (18"x8.5") doesn't get above 85F so I am dropping all fans from here forward. Temp on the dies by thermocouple is 85C so more than sufficient heat removal is accomplished with just the heat sink! All that you hear now is the water moving and the skimmer. It's very relaxing.

 

[Reef_Matrix29]

That is a great update about your tank and I was just sitting here trying to figure out how I was going to mount these fans, but maybe I will re-think it now. Then again I have that same size heatsink, but with 36 LED's on each....so perhaps I will still put a fan in the canopy, just not attached to the heatsink like I had planned before.

 

[TheFishMan65]

Thanks wesley that is what I was trying to say, maybe not quite as well I read a few pages back where someone had disconnected all the LEDs to test them I thnk cut the wires) - hopefully beween you and me that next person will understand that is not needed.

Heat Sinks - I read somewhere that the 3 watt LEDs are designed to be mounted to printed circuit board material. The stars can be moounted to aluminum sheeting. One advantage to running them in 2 parallel string is they will not get as hot - you actually get more lumens (light) per watt this way.

 

[der_wille_zur_macht]

<a href=showthread.php?s=&postid=15564605#post15564605 target=_blank>Originally posted</a> by TheFishMan65
I read somewhere that the 3 watt LEDs are designed to be mounted to printed circuit board material. The stars can be moounted to aluminum sheeting.

I can verify with (unfortunate) personal experience that these LEDs, even when mounted on stars, will burn out quickly without adequate heatsinking, even at 500 or 600mA drive current. IMHO it's better to over-design in this aspect rather than under-design.

 

[kecked]

heatsinks

heatsinks

Absolutely do NOT run these leds without a heatsink. My situation is that I have 24 leds on 7 pounds of aluminium. That is further mounted on 80/20 1010 frame giving another few feet of heatsink in open air. If you mount it in a canopy, you will need some type of small fan to keep fresh air over the heatsink.

I have been monitoring the light output of the array with a ccd camera calibrated for spectroscopy and have not seen any difference in light output between fan and no fan. I did see a steady drop of about 1% per month for the first two months and then it stabilized and has not changed. Once I took the fan off I detected a drop of about 2% in intensity from the time i turn it on until the temperature stabilizes in a few hours. That is the same as the drop level I saw from first run not a new 2% drop. It then remains constant and I have not seen a shift in intensity or spectrum. Let's see what happens in a few months. Until then keep your fans running.

I'm running my whites at 1000ma and blues at 700ma.