CMB16D: DIY Reef Tank LED Driver/Dimming Mode?

[Landsailor]

Hi,

I am in the process of building an LED fixture for my reef tank using 10W LED chips. By the time it's all said and done, I will probably have twenty or more of the chips in three or four different colors. The fact that the CMB16D has sixteen channels and can handle 20A per bank makes it an amazing cost per channel driver.

My LEDS have a forward voltage of 9-12V and a current draw of 900ma. I could easily run two of them in series to run 16 of them from one bank at 24VDC.

Is there any current limiting on the board or does that need to be implemented in the LED circuit? (via a resistor?)

How's the duty cycle on these?

Has anyone else done this?

Thanks!

Jason

[plasmadrive]

I just ordered my first CMB16D-QC boards the other day so I have no actualy first hand knowledge... with that said I doubt that there is any current limiting on the board itself. I believe these are PWM controllers with straight low side switching. You will have to have current limiting in your LED........

...However, you are saying your LEDs have a Vf or 9-12VDC. That sounds like they have current limiting in the LED circuit.. IT SOUNDS THAT WAY but it may not be. I would do a bit more checking on the specs of the LED. It could be that there are just several chips that are in series internal fo the LED fixture.

Just not enough info to give you exacting support.. sorry.

Edited August 17, 2012 by plasmadrive

[DownTown]

Awesome application. Good luck with your project. Let us see pics when you're done

D.T.

[Landsailor]

I talked to the tech guy. He confirmed that there is no current limiting on the board (as suspected) and that I would have to figure out the right value and current capacity resistor. The 10W units are just multi-die (3x3) on a single carrier.

I really like the capability to have sixteen channels of control. If you have a new coral that still needs to acclimate, you could dim the lights just over that area.

The downside is that I don't know how well the single program will handle all that. Dedicating a computer to run it 24/7 isn't alluring, but it's still cheaper than buying anything else available with tons more control.

[cenote]

Landsailor, curious, have you used LED's in tanks yet? Having problems with my LED's causing bad algae. Started off using just a small strip of 5050's both blue and white, and had a break out of brown algae, down to just 3 whites, seems to be ok.

yeah yeah yeah, I know, it's a holiday forum.

[Landsailor]

I have not used them yet, but there are many people who are. There's a great thread on Reef Central in the DIY section about Minimalistic Multichip LED like I'm using. I just setup my 125 after having a 55 for six months, so I'm far from an expert. My metal halides add so much heat and draw over 4 amps when they're running. I have a good ten months left on the lamps (Radium 20Ks), but I really don't look forward to replacing them at $90 each!

Are you using cool white or warm white LEDs? Do you run a refugium? I'm still just getting started, but I have a great skimmer and try to keep the macro algae fed well so there isn't any nitrate to feed the yucky algae. My brother owns a lawn service and he drew a parallel between a reef tank and the fertilizers he uses. "If you feed the good stuff well enough, there won't be enough food for the bad stuff" Weeds in his case, hair and brown algae in ours.

This might be a "holiday" forum, but it's also here to help LOR users (and sell product!), so I don't think anyone should mind.

I mentioned this idea to an Imagineer friend of mine. He's thinking about getting a couple of the DC boards to run LED lighting in his house and a miniature lighted fountain in his front yard.

[cenote]

Are you using cool white or warm white LEDs? Do you run a refugium? I'm still just getting started, but I have a great skimmer and try to keep the macro algae fed well so there isn't any nitrate to feed the yucky algae. My brother owns a lawn service and he drew a parallel between a reef tank and the fertilizers he uses. "If you feed the good stuff well enough, there won't be enough food for the bad stuff" Weeds in his case, hair and brown algae in ours.

Am using Cool white strips. Am not doing a refugium. The setup is a 75g fresh water setup. Have been able to get the brown algae under control threw chemicals. And sorry Dan B., I am just using two lamp timers with walwarts to drive the LED's.

[Greg Young]

I also used 2 metal halides (175 watt 10Ks) for a 75 gallon reef. I had them suspended over the tank enclosed in a ventillated wooden hood, so heat was never an issue. I used 2 actinics for an hour before and after the halides were on, to give transition time to the inhabitants.

I would be cautious about the true light range for LEDs, but then again I was always a little more picky, as I liked to raise and propagate hard corals. Just because it looks right, doesn't mean it will be (ie the brown algae issue, etc).

Greg

[robm]

great idea Lansailor. . I use to apex controller system on my reef tank. But what a great idea I wish I would have heard that 2 years ago!

[Iyamd]

So LandSailor and PlasmaDrive... Happy holidays! What is the status of your 16-channel Reef LED controllers?

I'd really appreciate your findings and recommendations before I go to buy the device.

Thanks!