DIY LED - Please check my plans

[Scuba_Steve]

I realize its a little late now that Ive already placed the order, but can someone confirm that Ive done my math right. This is my first LED build.

Ill be running 39 LEDs

25x XPG2 Cool Whites
14x XTE Royal Blues
5x Meanwell LDD 1500L
36V 9.7A 350W AC/DC Universal Regulated Switching Power Supply PSU

I will be running strings of 8 LEDs off each LDD.

 

[oreo57]

I realize its a little late now that Ive already placed the order, but can someone confirm that Ive done my math right. This is my first LED build.

Ill be running 39 LEDs

25x XPG2 Cool Whites
14x XTE Royal Blues
5x Meanwell LDD 1500L
36V 9.7A 350W AC/DC Universal Regulated Switching Power Supply PSU

I will be running strings of 8 LEDs off each LDD.

Nothing looks out of whack.. though I personally prefer not to drive LED's at "max"...

 

[Scuba_Steve]

From what I understood The LDDs have a Analog dimming feature. I was going to use that to bring them down to about 1350ma using an Arduino. Should I be able to use PWM dimming simultaneously while using analog dimming if I need to?

 

[oreo57]

From what I understood The LDDs have a Analog dimming feature. I was going to use that to bring them down to about 1350ma using an Arduino. Should I be able to use PWM dimming simultaneously while using analog dimming if I need to?

LDD-H and L's are PWM dimming only-ish.. (it is a bit confusing) .5-2.5V analog dimming w/ an initial start @ 20% for the 1000-1500mA series only apparently.
Few if any use it this way...
Arduino does PWM just fine..

As to simultaneous???

 

[reefermad619]

What color temp are you shooting for? Seems like a lot of cool white.

 

[Scuba_Steve]

Im not concentrating on color temp. I am going for maximum growout. I assume it will end up at around 10k though.

Kinda like what most recommend for growout with MH, get a Ushio 7k bulb. Not pretty but it works. At least with this I can turn down the whites to make it pretty when I want to .

I made a mistake BTW
24x cool whites
15x Royal Blues

I just got my heatsink and thermal adhesive in today. Unfortunately most of the rest is coming from China so it will take way longer. Now for the waiting game...

 

[Scuba_Steve]

Is there a better way to not run them at max? On small LEDs I would use a resistor, but these would require some awful big resistors correct?

 

[perkint]

Best way would have been LDD1000s, but that wouldn't have given you the ability to run at max if you wanted...

Tim

 

[oreo57]

but these would require some awful big resistors correct?

no....If you match a constant voltage power supply close to the cumulative V(f) of the emitter string at the mA output you want, the resistor can be small in Watt terms..well like 1 1/2 to 2..

At least in theory..

 

[zachts]

Not to derail your plans but for LEDs you know all most all the growth power comes from the blue end of the spectrum........ that would be your violets, royal blues, and true blues, whites (which are just royal blues with a little green and yellow phosphor thrown in) are pretty much only there for our human eyes for the most part......... as I recall the Ushio 7,000k pumps out a lot of red in the spectrum and a much broader blue end and doesn't really loom much like a cool white LED spectrum at all.