DIY LED Headache

NeveSSL · Mar 22, 2012

That is right, Bill, but in this case he doesn't need that much PAR is the point. This isn't an aquarium at all... only lighting plants.

Brandon

turbo21 · Mar 22, 2012

I run the same leds from aquastyle using the cheaper chinese drivers and i am growing coral on the sandbed of my 220. Been running them since september and have not had any issues.

I would think that you would not need to run the optics on your setup, your will have a better spread without them and the par loss will be minimal through the air

bob

stevenhman · Mar 22, 2012

Great info everyone! Thanks a bunch. I'm thinking of going with 48 with no optics (just in case I guess).

Does anyone know if a Meanwell ELN-60-48P (I need the PWM not analog 'D') could run 24 3w LED's (it's around 2.5w @700mA per LED actual - the LED's will be driven less, maybe 650/680ish) in one long series? The whole parallel string thing seems a bit...compicated when it comes to balancing out strings.

I guess I should use a 700mA quick blow fuze...and some sort of resistor?

poolkeeper1 · Mar 22, 2012

stevenhman said:
Great info everyone! Thanks a bunch. I'm thinking of going with 48 with no optics (just in case I guess).

Does anyone know if a Meanwell ELN-60-48P (I need the PWM not analog 'D') could run 24 3w LED's (it's around 2.5w @700mA per LED actual - the LED's will be driven less, maybe 650/680ish) in one long series? The whole parallel string thing seems a bit...compicated when it comes to balancing out strings.

I guess I should use a 700mA quick blow fuze...and some sort of resistor?

Yes, I have built several like that.
Bill

stevenhman · Mar 22, 2012

Awesome! Thanks Bill. Did you also do the whole Driver -> resistor -> fuze ( with "->" being the terminal blocks) like in this picture:

I won't need the additional block - this picture is from a 'D' driver setup.

I'm assuming I can safely manage the current with the internal pot (while testing) and once it's set for my 'max' mA - then connect it to the controller? I'm still a bit lost as to which resistor I should use and if a 700mA quick blow fuze is what I need.

You guys rock! I'll be sure to document the actual build part so maybe someone else won't have so many questions.

poolkeeper1 · Mar 22, 2012

stevenhman said:
Awesome! Thanks Bill. Did you also do the whole Driver -> resistor -> fuze ( with "->" being the terminal blocks) like in this picture:

I won't need the additional block - this picture is from a 'D' driver setup.

I'm assuming I can safely manage the current with the internal pot (while testing) and once it's set for my 'max' mA - then connect it to the controller? I'm still a bit lost as to which resistor I should use and if a 700mA quick blow fuze is what I need.

You guys rock! I'll be sure to document the actual build part so maybe someone else won't have so many questions.

Not quite that elaborate just Fuses to terminal Block/Drivers but It's working great for almost a year. And my Corals have never looked better.
Bill

stevenhman · Mar 22, 2012

Sweet. Just ordered LED's (from aquastyle) and drivers from onlinecomponents.com.

CJO · Mar 23, 2012

poolkeeper1 said:
Yes, I have built several like that.
Bill

In series? That requires significantly more voltage than the 48 volts for which that driver is rated.

Creating two balanced, parallel strings sounds harder than it really is. It added another 10 minutes onto my build and I did it back before there were many directions on how to do it efficiently.

CJ

stevenhman · Mar 23, 2012

Thanks a lot CJ - after looking at a couple of nice DIY posts with plenty of pictures I guess it isn't out of my range of ability.

Would you agree that I could run 2 parallel strings of 12 (for 24 total) on each driver? Do you think a resistor is necessary and if so what kind (hahaha)?

The only quick blow fuses I could find that were 700mA are the glass tube kind. I'm guessing I can just mount them in a fuse block like this?

the other alternative wold be an in-line fuse holder:

NeveSSL · Mar 23, 2012

If I'm not mistaken, the resistor isn't necessary but is used to measure the voltage. I'm not getting into the math of it, though... lol If you get an accurate (1%) resistor at 100ohm, you can measure how much voltage the string of LEDs is using by measuring how much voltage the resistor is dropping and multiplying it.

Brandon

haysanatar · Mar 23, 2012

why not just wire them in series.... tons easier..
not to mention when led's blow they disrupt the current anyways... sort of like those crappy christmas lights where one bulb takes down the strand.
way less headache.

NeveSSL · Mar 24, 2012

Its not really that big of a deal. You can do this with a tiny bit more thought than a series string. And that just involves making sure both strings pull the same voltage. Even then, a lot of people pull this off without even making sure the strings are balanced. Its just an extra $0.20 fuse to replace if you do lose an LED compared to a series string. Not really a big deal.

Brandon

poolkeeper1 · Mar 24, 2012

NeveSSL said:
If I'm not mistaken, the resistor isn't necessary but is used to measure the voltage. I'm not getting into the math of it, though... lol If you get an accurate (1%) resistor at 100ohm, you can measure how much voltage the string of LEDs is using by measuring how much voltage the resistor is dropping and multiplying it.

Brandon

The way it was explained to me is that the resistor keeps voltage from surging and causing problems like burned Led's It's kinda like the regulator of the Voltage, But I may be wrong?
Bill

CJO · Mar 24, 2012

You can run two string of 12 Leda's in parallel with those drivers at 700mA.

The resistors are just there to make it easier to set your current.

CJ

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