DIY LEDs - The write-up

[TheFishMan65]

MosMike, who says the XM-L will be running hotter? I admit they will be running at 2 watts (.7ma * 2.9 volts) and the XP-G at one watt (350ms * 3 volts). Are you just assuming they will be running hotter or did I miss something?

 

[MosMike]

MosMike, who says the XM-L will be running hotter? I admit they will be running at 2 watts (.7ma * 2.9 volts) and the XP-G at one watt (350ms * 3 volts). Are you just assuming they will be running hotter or did I miss something?

That's correct. The XM-L will have to dissipate twice the power in the same small footprint. It should be noted, that the lumen output of Cree LEDs is specified with a die temperature of only 20C !

 

[Belgian Anthias]

Xp-g

Xp-g

Very simple:
XM-L T6 - $7.90 280lm @700mA 35lm/$1
XP-G R5 - $4.90 139lm @350mA 28lm/$1

The 7 lumen per dollar difference can be "destroyed" by the fact that XM-L die is running hotter at a higher current. Actually an active cooling of the LEDs can increase the lumen output by 5-10%.

XP-G can run at max 1500mA 490 lumen = 100lm/$1

 

[der_wille_zur_macht]

Very simple:
XM-L T6 - $7.90 280lm @700mA 35lm/$1
XP-G R5 - $4.90 139lm @350mA 28lm/$1

The 7 lumen per dollar difference can be "destroyed" by the fact that XM-L die is running hotter at a higher current.

This is the very definition of apples to oranges! Compare the numbers when the currents are the same. Otherwise we could contrive things to make just about any LED look better than any other LED.

Plus, IMHO, it's fairly useless to use only upfront purchase cost when computing cost efficiency. You only pay upfront cost once. If you keep the unit 2 years vs 10 years, upfront cost is a very different proportion of the total cost of ownership.

 

[MosMike]

This is the very definition of apples to oranges! Compare the numbers when the currents are the same.

Then the XM-L will deliver 160lm @350mA and it will give 20lm/$1
It's like using a Ferrari as golf cart - not very interesting.

Nethertheless, XM-L is the way to go. What can be the RB & XML mix if both are run @700mA ?

I found a nice online supplier of U channels: http://www.onlinemetals.com/merchant.cfm?pid=6992&step=4&showunits=inches&id=297&top_cat=60

 

[chris023]

Okay, I need some help please, sorry if this sounds like a bunch of long winded babble. I think I have read/researched sooo much that I think I go stupider. Just when I think I understand, I get confused again.

I want to LEDify my 60x24x24 SPS reef from T5s. My main issue is the Driver(s) and understanding what is needed to power the LEDs.
I did make a 12 LED dimmable module for my 20 gallon frag tank (picture below), which I used a RapidLED kit that came with the ELN-60-48P and I trusted what I was advised that this driver will handle the 12 LEDs. Thanks again to all you who helped me out with that first rig (you probably know who you are =). I now think I understand how to determine how many LEDs a driver can run based on the formula called out so many times in this and other threads:

driver voltage / forward voltage of LED = number of LEDs you can add to driver.

In the case of my previous mentioned frag module : 48 (volts of driver) / 4 (forward voltage – not sure if this is actually right, heard that ~3.5 is more like the avg) = 12 (number of LEDs). I run these LEDs at 800ma which is well under the max 1.3 amps this driver is capable of.

So I want to run approximately (not 100% determined until I understand more on drivers) 96 LEDs for my tank (60x24x24 sps). Based on another guideline (on these threads) of: Length X Width / Number of LEDs = 15. 15 being the target number for SPS. I think I want to set these up in series based on the complexity/dangers of running in series/parallel may be too risky for my electrical skill set (if that isn’t already obvious). I will probably configure them on U-Channel lengths as heat sinks, with say 18 LEDs 3 inches apart for 54 inches. Will probably need to make 6 of these ‘rails’, actually totaling 108 LEDs. Again the configuration is all just a possible option at this point in the process. I want to run over almost the whole length and width of the tank as I have pretty much got full grown colonies covering most of the tank (see picture below). Please provide any feedback on this aspect of this build.

The big question is what driver(s) should I use to run as many LEDs together as I can??? Definitely don’t want to do more than say 3 or 4 drivers total as I believe (based on reading threads) that will become counter-productive and possibly dangerous? I thought I could just bump up to a driver that could handle more than 12 LEDs (HLG series?), but I am having trouble understanding how? It seems like I need more volts, but the max volts on any of these drivers is 54, correct? So those drivers would only power maybe 16 per string, correct? Seems like the watts on these drivers are the major increasing factor, but I’m not sure that wattage is the concern here (although I could be very wrong).

I probably should just stop and let you all set me straight. Thanks in advance for your help. :beer:

pic of my 12 LED frag module:

pic of my current tank that I would like to LEDify

 

[kcress]

Okay, I need some help please, sorry if this sounds like a bunch of long winded babble. I think I have read/researched sooo much that I think I go stupider. Just when I think I understand, I get confused again.

I want to LEDify my 60x24x24 SPS reef from T5s. My main issue is the Driver(s) and understanding what is needed to power the LEDs.
I did make a 12 LED dimmable module for my 20 gallon frag tank (picture below), which I used a RapidLED kit that came with the ELN-60-48P and I trusted what I was advised that this driver will handle the 12 LEDs. Thanks again to all you who helped me out with that first rig (you probably know who you are =). I now think I understand how to determine how many LEDs a driver can run based on the formula called out so many times in this and other threads:

driver voltage / forward voltage of LED = number of LEDs you can add to driver.

In the case of my previous mentioned frag module : 48 (volts of driver) / 4 (forward voltage "“ not sure if this is actually right, heard that ~3.5 is more like the avg) = 12 (number of LEDs). I run these LEDs at 800ma which is well under the max 1.3 amps this driver is capable of.

So I want to run approximately (not 100% determined until I understand more on drivers) 96 LEDs for my tank (60x24x24 sps). Based on another guideline (on these threads) of: Length X Width / Number of LEDs = 15. 15 being the target number for SPS. I think I want to set these up in series based on the complexity/dangers of running in series/parallel may be too risky for my electrical skill set (if that isn't already obvious). I will probably configure them on U-Channel lengths as heat sinks, with say 18 LEDs 3 inches apart for 54 inches. Will probably need to make 6 of these "˜rails', actually totaling 108 LEDs. Again the configuration is all just a possible option at this point in the process. I want to run over almost the whole length and width of the tank as I have pretty much got full grown colonies covering most of the tank (see picture below). Please provide any feedback on this aspect of this build.

The big question is what driver(s) should I use to run as many LEDs together as I can??? Definitely don't want to do more than say 3 or 4 drivers total as I believe (based on reading threads) that will become counter-productive and possibly dangerous? I thought I could just bump up to a driver that could handle more than 12 LEDs (HLG series?), but I am having trouble understanding how? It seems like I need more volts, but the max volts on any of these drivers is 54, correct? So those drivers would only power maybe 16 per string, correct? Seems like the watts on these drivers are the major increasing factor, but I'm not sure that wattage is the concern here (although I could be very wrong).

I probably should just stop and let you all set me straight. Thanks in advance for your help. :beer:

First off, for being "stoopid" you seem to have a pretty good bead on things..

You only go a little off the rails towards the end.

Once you have an estimate of how many LEDs you want to use you have to figure out what driver(s) to use and then work backwards to find exactly the number of LEDs you can have. From there you return to how to lay out reasonably that number of LEDs.

IMO don't bother with 54V drivers unless the numbers shake out really specially that way.

You should go with parallel strings....

Looking for about 96 LEDs.

3.3 x 0.8 x 96 = 250W

If you are up for mixing the colors then this can easily be handled with a single driver. If you are going to screw with the color balance then you will need two drivers. Which drivers can't be determined until you answer that question.

 

[mseepman]

I have to say that I understand where the fear of parallel builds comes in. Today I received 180 Cree XP-G and XP-E LED's and figuring everything out has my head spinning.

 

[kcress]

Take a breath..

Sit down and do it like you'd eat an elephant.

Do it one bite at a time...

 

[chris023]

First off, for being "stoopid" you seem to have a pretty good bead on things..

You only go a little off the rails towards the end.

Once you have an estimate of how many LEDs you want to use you have to figure out what driver(s) to use and then work backwards to find exactly the number of LEDs you can have. From there you return to how to lay out reasonably that number of LEDs.

IMO don't bother with 54V drivers unless the numbers shake out really specially that way.

You should go with parallel strings....

Looking for about 96 LEDs.

3.3 x 0.8 x 96 = 250W

If you are up for mixing the colors then this can easily be handled with a single driver. If you are going to screw with the color balance then you will need two drivers. Which drivers can't be determined until you answer that question.

Just to ensure I am on the same page...what is the 0.8 in your above numbers...current? (3.3 = forward voltage, 96 = total LEDs, 0.8 =?)

I think I have a good idea of the number of LEDs (give or take a few). Lets say I want to run 6 u-channels with 18 LEDs per u-channel = 108 LEDs. Colors will be mixed per u-channel.
I will be running these at .7 amps...so 3.3 x .7 x 108 = 249.48
so the HLG-320-?
wouldn't each string need ~60 volts in this case (18 LEDs per string x 3.3 = 59.4? Is that correct?)

I think I get the concept of parallel strings based on page 200 (and other threads), although the consensus seemed to be not to go with parallel. Maybe that is just for smaller setups. I just don't fully understand the wiring.
Other concerns with parallel I have as a electrical newbie: each strings total forward voltage needs to be basically the same; you need the correct resistors and fuses on each string, etc.
I'm pretty sure I can overcome those concerns if parallel is the way to go...

 

[chris023]

I have to say that I understand where the fear of parallel builds comes in. Today I received 180 Cree XP-G and XP-E LED's and figuring everything out has my head spinning.

wow! spinning is turning into an understatement :spin1:
what size tank are you putting them on and how are you wiring/driving them?

 

[kcress]

:furious::furious::furious::furious:

I spent 20 minutes on this answer and it vaporized.

So will give the budget repeat.

LED drivers are categorized by wattage. You need to come up with a ball park wattage to know where in the families to look.

Watts = 3.3V x 0.8A x the total number of LEDs.

Once this is known you look at the 60, 100, 120, 150, 200, 250, 320 watt models.

The parallel isn't real hard.

Here's the basic setup:

The resistors are all the same value so you don't have to think about 'different values'.

You'll use them to shift around a few LEDs to get the strings matched current wise.

 

[MosMike]

chris023
I have encountered the same problem as you. I wanted a long string of LEDs. After browsing the web I understood that Mean Well drivers are actually poorly designed.
I found a manufacturer of better LED drivers, here is the datasheet for their 100W model: http://www.inventronics-co.com/uploads/DS-EUC-100SxxxST 20100531 E.pdf
For your setup you will need 2 such drivers, 1 long string per driver.
I have contacted the manufacturer and I am waiting for their response.

 

[TheFishMan65]

MosMike, looks interesting any idea on the price? The only issue is that is does not support dimming so there is no easy way to adjust color. Of course I set all mine to 500 ma turned it on and liked it, but someone else might not

 

[MosMike]

MosMike, looks interesting any idea on the price?

I think they are more expensive than MeanWells.
Also they have models with dimming, but in other wattages. I plan to order samples and have them dissected. :smokin:

 

[TheFishMan65]

I came across an old (2006), but IMHO interesting article while trying to figure out how many watts of LEDs equal how many watts of MH. The article deals with the Solaris - does anyone know if they ran a a true 3 watts?
Product Review: A New Horizon in Lighting: PFO's Solaris LED System

 

[der_wille_zur_macht]

I don't think we can draw any conclusions based on the Solaris units. From what I've seen, they didn't even use the same MODEL of LED from unit to unit, much less the same bin.

PS I think your link is broken.

 

[TheFishMan65]

Try this Product Review: A New Horizon in Lighting: PFO's Solaris LED System

I also found this article (still reading) that talks about CREE. Anyone know what generation CREE the Tropic Marine Center AquaRay or AquaBeam use?

It is still easy to make assumptions from the raw data based on this study with plants that a 12 Watt LED can at least replace a 100 watt MH of equal Kelvin ratings in aquarium applications (the TMC AquaBeam 1000; 30 Watt LED should easily replace one 175 Watt Metal Halide of similar rating (14,000K for example) for marine applications.

 

[TheFishMan65]

This is cool also (if true)

Use of LED to prevent Red Slime

Another positive attribute of LED Aquarium lights as per a recent study (August of 2009) is that LED used in marine aquariums that suffer with Marine Red Slime Algae (Cyanobacteria) can immediately eradicate Red Slime algae when used in a full spectrum lighting configuration. These “immediate” results were just two weeks all the while other lighting configurations (such as switching to 6400 K CFL from 10,000K CFL) show slight improvement, the LED lights showed much more dramatic results. I do not know (as of this update) the exact reasons, but my suspicions is that CFL (including VHO & SHO) still produce more of the yellow/green nanometer range of light which encourages Cyanobacteria and discourages more discourage competing green algae.

 

[mseepman]

So, in taking my first "bite" of this elephant and given the math that I've seen all through this thread (thanks so much Kcress), would the following setup work...
96 XP-E RB hooked up in 8 parallel strings of 12 running on an HLG-320H-48B at 800mA
72 XP-G Whites hooked up in 6 strings of 12 running on another HLG-320H-48B at 1000mA
Please assume that I will get the fuses, resistors terminal blocks and cooling done correctly (as you can see, I believe in miracles, lol)
In looking at the data-sheet for this driver (http://www.cdiweb.com/datasheets/meanwell/HLG-320H-spec.pdf) can I assume a controller with the right 1-10V module will be able to dim these?