DIY LED lighting MH replace

[speedstar]

Well I just got this working on a bench it now needs to be mounted in a hood and I'll take some pics. I'm going todo a coral growout comparison also with SPS frags. My LED solution VS MH 250w.

Basically built a power supply that has varible voltage (though fixed) variable current (for dimming). The big cost is the transformer and LED's $4 each, but I had several tx's to salvage. The PS then puts out 30V @ 5 amps. Using a op amp for current control.

This then drives the LED's in a series par combination. The cost for a 49LED (luxeon III's) array and power supply is $250. I'll post the schematics for the power supply and LED config but this is experimental and USE AT YOUR OWN RISK!
I used the white 5500K LEDS and the blue 470nm Blues.

 

[smcdonn]

Awsome man. I would like some pictures

 

[don954]

How did you mount them? Ive been thinking of just doing a one-off PC board and baking them on. Pictures?

 

[speedstar]

I bought the STAR's not just the emitter so they come mounted on an easy to use PCB board that also kinda acts as a heat sink. Then I used a heat sink epoxy to mount them all on a makeshift heat sink. Theses are the stars i used u can see it is on a neat little board already.

http://www.lumileds.com/products/family.cfm?familyId=8

 

[easttn]

KEWL.

 

[speedstar]

Here is the power supply diagram. Also the LED's are series of 7's use from 5 to 7 rows. At 5 rows they will be driven harder than you may want.

 

[easttn]

Harder than 350mA per leg?

 

[ClownReef®]

Is it gonna be like a DIY PFO Solaris???

 

[speedstar]

the current per leg is the 5amp/ amount of legs. The luxeon III's can take over a amp but will wear out quick. The lexeon I's can only handle 350ma.

 

[speedstar]

<a href=showthread.php?s=&postid=8059531#post8059531 target=_blank>Originally posted</a> by ClownReef®
Is it gonna be like a DIY PFO Solaris???

I avoided mentioning any names.

I am experimenting with several different PS solutions still. I know there are better ways and control but started real basic to see em all light up.

 

[ClownReef®]

..I said Solaris because theres nothing out there (that i know of) to compare it to.

 

[easttn]

Missed the III, sorry. A few q? if I may..
What binning codes are you using?
Why did you not select the V's for white?
Will the 470nM LEDs be controlled seperately from the whites?
Are you going to use any thermal management other than the star base?

Thanks.

 

[Qwiv]

The other Blue LED's have much higher PAR. FYI. Did you put lenses on the LED's? They really help. How did you take care of moisture?
I built one to, but am using the K2 LED's @1500mA which is way bright. Also have a PIC controller that dims them over the day and controls the moon lights. Perfect dusk/dawn transition. I am using the fixture in a special nano tank. We are making a web page for it soon, as it has some other special stuff that is not light related.

Can't wait to see a pic of yours.

 

[em21701]

Just a note on driving LED's, they are best driven with a constant current. The constant current significantly reduces color and brightness differences due to forward voltage variation of each LED. If you want a dimming feature use Pulse Width Modulation (PWM) of the constant current. By varying the duty cycle of the PWM you'll dim the light accordingly with no risk of under/over driving the LED's. Qwiv, I would assume that the PIC you are using is doing just that? I'd love to know more about how you are using the PIC, does it have and RTC onboard or did you use and external one? Care to share the source code? I have been studying LED lightinig for a while, I hope to get into building a setup myself.

 

[speedstar]

I bet them are real bright I thought about the K2's first and backed down to the 3's. Looks like you have already taken this the direction I was planning to with the pic chip. I was gonna see if they will work with SPS's first. By other blue do you mean the more purple royal-blue @455nm? Thanks

<a href=showthread.php?s=&postid=8059989#post8059989 target=_blank>Originally posted</a> by Qwiv
The other Blue LED's have much higher PAR. FYI. Did you put lenses on the LED's? They really help. How did you take care of moisture?
I built one to, but am using the K2 LED's @1500mA which is way bright. Also have a PIC controller that dims them over the day and controls the moon lights. Perfect dusk/dawn transition. I am using the fixture in a special nano tank. We are making a web page for it soon, as it has some other special stuff that is not light related.

Can't wait to see a pic of yours.

 

[BeanAnimal]

The atmels have built in PWM... just a few lines of code is all you need. Kinda OT here though

 

[Zackb911]

PICS!!

 

[danielboun]

Growing corals with L.E.D's. Waaay cool. any pics ?

 

[speedstar]

Im just getting the systems up for test and comparison

 

[xtrm suv]

got to see this one... great idea!!