LED Light Build for 30 Gal Oceanic Cube **Updated 100% done with pics**

[McJosh13]

The other issue is if one LED fails shorted, and that string is now over volted. Now you run the risk of killing all LEDs in that string.

 

I agree that is also a possibility

[evilc66]

Fortunately, that failure mode is less likely than it failing open.

[Crazy Tiki]

Hey McJosh,

 

I was wondering if you had a basic wire diagram.

 

From reading your current mirror topic you set up a LM317 circuit that Cptbjorn recommended, was that just to test the Led's for vF? Or did you incorporate that in the array as a way to control voltage? If so can you explain why? Also just to confirm you do not have any current mirrors or current overload circuits in your build

 

thanks,

[McJosh13]

Crazy Tiki,

 

Don't have a wire diagram, each meanwell driver has 3 parallel strings of 7 leds, no current mirrors or current overload circuits just simple series/parallel wiring. The first meanwell is wired up to 21 Royal Blue leds and the second meanwell is wired to 19 white and 2 royal blue leds. The 3 UV leds are wired to a separate luxdrive constant current power supply I had sitting around and the moonlight is wired to a old nokia phone charger.

 

I didn't test the leds for their vF's or anything, just wired them all up then when it was done, checked the current going through each string to make sure they were pretty close, that's it.

 

I am using 2 LM317 circuits to vary the input voltages to the control wires of the meanwells (0-10v.) I used this circuit because I thought it would give me full dimming, but it turns out that I only get dimming down to about 50% because the meanwells want PWM signal not variable voltage. This limited dimming is ok for me because the only reason I ever need to dim the lights is for acclimation of new coral and I never go down past 50% anyways. Although, if I was starting over I would build PWM circuits instead as they should provide full dimming, I just don't feel the need to do it now.

 

If you still think a wiring diagram would help I could draw something up on Fri after my pharmacodynamics exam.

[Neto]

The other issue is if one LED fails shorted, and that string is now over volted. Now you run the risk of killing all LEDs in that string.

 

What if you add 1 A fuses on each led array?

[evilc66]

LEDs will blow faster than the fuses. Anyway, fuses protect against over current, not over voltage.

[Crazy Tiki]

Thanks for the explanation. I forgot about the whole powered dimming function, in my quest for the current mirror circuit- and the journey continues.