# LEDEngin - 10 watt / 15 watt Information thread



## HarryN (Jun 5, 2009)

Hi, There are not a lot of posts about the LedEngin products but they are actually quite interesting. They feature quite low thermal resistance, use a glass lens (cover) and have quite reasonable output. 

I would like, if it is ok, to get a thread going about information for using these LED packages. (sort of like the similar K2 Information Thread) This would include questions / inputs about mechanical aspects, drivers, and optics / reflectors.

In my particular case, I am mostly interested in the 10 watt part and how to manage the light (optics / reflectors), but feel free to post on the other versions if you wish.

Just to kick things off, here is a link to their web site product list.

http://ledengin.com/led_products.php


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## saabluster (Jun 5, 2009)

Have you seen how much space is in between the dies? Talk about a doughnut. I don't think anyone sees why it would be better to have one of these instead of a MC-E or P7.


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## csshih (Jun 5, 2009)

I've had one of those LEDs.. nifty little thing.. I remember it ran extremely hot :shrug:

the new multicolor MC-E should work better


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## HarryN (Jun 5, 2009)

saabluster said:


> Have you seen how much space is in between the dies? Talk about a doughnut. I don't think anyone sees why it would be better to have one of these instead of a MC-E or P7.



That is an interesting point saabluster, and it might explain why there is so little posted about it. The aspects that I like about it 
- The extremely low thermal resistance - about 1/2 of many packages
- Much tougher "lens"
- Thermal isolation of the phos from the die

I know that they have been playing with the lens optics to work on beam shaping, so maybe that helps with die spacing. :shrug:

Frankly, I also like the fact that the die are US made (Cree die I am pretty sure) and they are also packaged in the US (CA). I have been to the factory a few times - kind of neat. (no free samples though)

csshih - I am just curious - what did you do for optics / reflector, thermal path and driver for this package ? Any pics / suggestions ?


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## moviles (Jun 5, 2009)

HarryN said:


> In my particular case, I am mostly interested in the 10 watt part and how to manage the light (optics / reflectors), but feel free to post on the other versions if you wish.
> 
> Just to kick things off, here is a link to their web site product list.
> 
> http://ledengin.com/led_products.php



the 10w and 15w version are [email protected]:thumbsdow

I want a sst-50 and sst-90 now!!!!!!!!!!!!!!!!!!
https://www.candlepowerforums.com/threads/224644


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## kaszeta (Jun 5, 2009)

I haven't yet used the 10 watt package, but I use the 15 watt UV and Dental blue ones pretty often at work.

What's good:

1. Packaging on the 15 watt unit is really nice (+/- leads mounted on a flexible ribbon).
2. Thermal resistance to the base is really, really low, so just mounting these on a good heat sink seems to provide adequate cooling despite their generating a lot of heat

What's frustrating:
1. The UV ones have a 65 degree half angle or so spread. Not bad for a lot of applications, but very difficult to focus down if you want a tight beam. I've had some decent luck using some FCM series lenses from Fraen to concentrate the 15W light output down to a 8 degree cone.

I've been trying to get some really high UV densities (I'm shooting for around 20-30 emitted UV watts focused down to a few mm^2), and these haven't been a bad starting point for my efforts.

If anyone else is running something with at least 3 or 4 of the 15 W units, I'd be interested in knowing what drivers they are using (I'm using a really beefy bench supply at the moment)

Here's my "Dental Blue" module:


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## saabluster (Jun 6, 2009)

HarryN said:


> - The extremely low thermal resistance - about 1/2 of many packages
> - Much tougher "lens"
> - Thermal isolation of the phos from the die
> 
> I know that they have been playing with the lens optics to work on beam shaping, so maybe that helps with die spacing. :shrug:


You are right that it does have a very low thermal resistance. But it doesn't really seem to be helping them. The MC-E has a glass lens also but is not saddled with a pasture in between the dies. And the thermal isolation of the phosphor is nice and good for fixed lighting but has no real benefit for portable lighting. The gap in the dies is a real big deal here. It is a deal breaker. And as moviles mentioned driving these would be difficult in most lights. There is a very good reason you do not see these in lights.


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## HarryN (Jun 6, 2009)

moviles said:


> the 10w and 15w version are [email protected]:thumbsdow
> 
> I want a sst-50 and sst-90 now!!!!!!!!!!!!!!!!!!
> https://www.candlepowerforums.com/threads/224644



Hi, this is an incomplete understanding of the packages and test conditions.

The data sheet shows that each LED die is individually powered with its own pads. There are two star versions, one for driving them in parallel, one for driving them in series. 

The die binning for Vf is quite tight, and is tested both "per die" and "as a package in series. It is the "in series" Vf that is reported. The Vf of this is going to be in the same range of any other power LED package.

One of the things I like is that they are really paying attention to Vf. Cree makes nice products, but one thing that always bothered me is that they kind of go to some bother to not spec Vf - kind of annoying to someone used to buying premium binned Lumileds products.

I don't disagree that the SST packages are very interesting, and it is not my goal to cut down anyone's products, rather, I am just trying to gather experiences and technical info on the product in one place.

It could well be that this is a great package for general lighting as you have noted. That would fit into the general nature of this forum, as we certainly have a general lighting category here. I don't use 5mm LEDs to power flashlights either, but that doesn't make them uninteresting for the right application.

You might be interested to know that my initial impression of the Cree packages, especially their initial 1 die packages, was that they were better suited for general lighting than flashlights. My wife, who cares very little about flashlights, was watching me test them against a Lux III (several years ago). The Cree package produced a soft white light effect due to putting the phos on the inside of the dome, while the Lux III package was clearly a hard white effect - more like an uncoated light bulb. The strong blue ring effect, common at that time, did not show up until you used a reflector with it, making them nearly useless with reflector applications.

At that time, Cree's package had not yet caught up with PL, so they have come a long way.

Coming back to the optical aspects - has anyone actually tried putting a reflector or optic on this package?


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## csshih (Jun 7, 2009)

HarryN said:


> csshih - I am just curious - what did you do for optics / reflector, thermal path and driver for this package ? Any pics / suggestions ?




Sorry.. I played with it a while back before I found CPF.. :O

I had it AA'd to a PC heatsink... and DD'd individual dies for short periods of time.. let's see if I can dig up a pic..


eh..
only a pic from my old sale thread of the emitter..


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## purduephotog (Jun 9, 2009)

I own 5x of the 660nm 10W LedEngin LEDs. I originally bought 4 for use with a grow light but one suffered 'pad breakthrough' and shorted out. 

This is due to my error, I'm sure- I use a multi meter to test that none of the pads were grounded and I'm guessing I poked it hard enough to go through the resist into the aluminum base. Why it happened on one and not all 4 I don't know, but it did.

The chips have a remarkably low c/w which allows a simple aluminum bar and heat sink to passively cool them. I have not hooked up a whisker/rice thermister to measure the temperature but use of an optical IR meter (insert reliability jokes here) states they do not exceed 130F after several hours of use in an open environment.

Soldering them was difficult as you might expect for such a highly efficient thermal pad.

They're running 2x2 with a 40W Xitanium driver- so not getting a full 1A each.

My plants like them- home grown lettuce did quite nicely.

I hope to purchase some Ledli optical reflectors at some point and rework the whole unit- but that'll be another day in another basement I hope.

Jason

-edit: Oh yeah, you can not buy replacement MCPB boards. I've tried and I did just find a note from LedEngin that they might have one to send me- there are specific boards because the contacts have to be soldered in place... not for the home user I'm told.


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## HarryN (Jun 9, 2009)

Hi Jason - Thanks for the post info.

When you talk about the contacts - are you talking about the contacts on the LED emitter version or the board?

I was planning to use solder paste to solder them on to a board. Did you use this method or something else?

Thanks

HarryN


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## HarryN (Jun 9, 2009)

kaszeta said:


> I haven't yet used the 10 watt package, but I use the 15 watt UV and Dental blue ones pretty often at work.
> 
> If anyone else is running something with at least 3 or 4 of the 15 W units, I'd be interested in knowing what drivers they are using (I'm using a really beefy bench supply at the moment)



Hi Kasteta - Thank you for posting that info here, and welcome to CPF.

Since you are running up around 50 - 60 watts, I think you are in Xitanium driver territory. They come in various power levels, some wtih dimming. I know that leddynamics carries at least one model. They are made by advanced transformer.

Good luck with your project and let us know you it works out.


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## purduephotog (Jun 9, 2009)

HarryN said:


> Hi Jason - Thanks for the post info.
> 
> When you talk about the contacts - are you talking about the contacts on the LED emitter version or the board?
> 
> ...



I ordered MPCB serially connected devices. So I broke through the solder pads on the aluminum board. I have not removed the LED /dies from that one yet.


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## FernanDEL (Sep 10, 2009)

kaszeta said:


> I haven't yet used the 10 watt package, but I use the 15 watt UV and Dental blue ones pretty often at work.
> 
> What's good:
> 
> ...


 
I'm interested by LZ4-00xx15 series but i don't know how the plug that (i have no knowledge in electronic). Ideally i want to plug a group of 3 and a group 6 on each powersupply, but if it more simple, i will be happy to connect them individually.

I want to use these 15w leds at their max power 1500mA, somebody tell me that i need driver for that and he suggest to use KONLUX DC 1500mA.
What i understand is i need one per Led and i have to find a powersupply with enough power to connect driver and cpu cooler.

If somebody can help me to open the Doors, because i need to Light my fire. ;-)


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## HarryN (Sep 10, 2009)

FernanDEL said:


> I'm interested by LZ4-00xx15 series but i don't know how the plug that (i have no knowledge in electronic). Ideally i want to plug a group of 3 and a group 6 on each powersupply, but if it more simple, i will be happy to connect them individually.
> 
> I want to use these 15w leds at their max power 1500mA, somebody tell me that i need driver for that and he suggest to use KONLUX DC 1500mA.
> What i understand is i need one per Led and i have to find a powersupply with enough power to connect driver and cpu cooler.
> ...




Hi FernanDEL - nice project.

With those kind of power needs, I am assuming that you are plugging it into a wall socket? There are AC drivers out there, Xitanium type. I think LEDSupply sells them, or at least can refer you to someone that does.

It might be possible to run several fully in series, but I think the Xitaniums max is around 25 - 30 volts Vf, so that is perhaps 8 junctions at full power.

Take care,

Harry


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## FernanDEL (Sep 10, 2009)

HarryN said:


> Hi FernanDEL - nice project.
> 
> With those kind of power needs, I am assuming that you are plugging it into a wall socket? There are AC drivers out there, Xitanium type. I think LEDSupply sells them, or at least can refer you to someone that does.
> 
> ...


I presume i need this one for my 1500mA:

*40-Watt Xitanium LED Driver Features:* 
Output Current: 1750mA 
Input Voltage: 120VAC 50-60Hz 
OutPut Voltage: 24VDC 
Output Power: 40W 
No Lead 
UL Class 2 - Outdoor Rated 

It's 60$
Ok i can easyly plug 6 led, is it enough power for 6 CPU coolers too ? What i understand is i have to use resistance to balance power right ?

Thanks


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## FernanDEL (Sep 13, 2009)

What i understand now it's i'm no need power to cool the leds :

ECC-00499-01-GP (13.5W)

Dimension 35f x 200 mm 
Heat sink Al. base + Heat pipe 
Finish Painting Color 
LED type LZ4-x0xx15 
Thermal resistance* RT=3.1°C/W 




Now i have to find how to balance power of the 40-Watt Xitanium LED Driver for having the best luminous performance without stressing the leds.

I will use 4 x LZ4-00R215 deep red (no spec) and 2 x LZ4-00B215 blue. What i don't understand in the specs is the bin code - Is it related to part revision, more recent are more performant ?

Any help are welcome ;-)


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## FernanDEL (Sep 15, 2009)

What i understand about electricity now is when i plug serial i add volt and when i plug parallel i add amp. For plugin 6 ledengin 15watts i have 4 possibilities (6 serial, 6 paralllel, 3 par. x 2 serial) and 2 par. x 3 serial). The problem is wattage, How many watts is needed for each solution.

Somebody know ?

PS: Ledengin Bin code is related to production batch if you are lucky you can get a good batch, or you can wait for a production reach your specificity.


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## bshanahan14rulz (Sep 15, 2009)

Watts is Current times Voltage (P=I*V)

if an individual LED pulls 700mA (0.7A) at 3.6V, it uses 2.52W (3.6*0.7=2.52)

if 3 of these LEDs are in series, their voltages add up (as you already know) So:
3.6+3.6+3.6=10.8V total voltage "dropped" by the string.
current flows through the whole string, the whole string sees 0.7A.
Now, crunch the numbers to get 7.56W used by this string of 3.

if 3 of these same LEDs are paralleled, their current adds up. So:
Each loop of the circuit goes from battery, through one LED, and back to battery. Since it only goes through one LED, the voltage dropped is 3.6V.
Current adds up when it has to split like that, so 0.7+0.7+0.7 = 2.1A.
Crunching the numbers gets you 7.56W used by these 3 LEDs in parallel.

You will notice, using the same components but arranging them differently will yield the same amount of power. In fact, if you multiply the 2.52 we got in the first example by 3, we get 7.56 since there are 3 LEDs instead of just one!

test is next week you better study!


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## FernanDEL (Sep 15, 2009)

bshanahan14rulz said:


> test is next week you better study!


 
Thanks prof, but the initial question is how to plug 6 ledengin 15w at 1500mA and 15v.

I have already said that i have no knowledge in electricity nor electronic, but by the way it looks like that i will reach the solution by myself. ;-)

At this time, i dunno if it work but i find a power supply near what i want. 

With a PowerPartners *Model Number *PPLC100S278SS :
*Current (1) : *2780 mA 
*Input Voltage : *90 ~ 264 Vac 
*Max. Output Voltage : *36 Vdc 
*Max. Output Power : *100 W 
*Typical Efficiency (2) : *91% 
*Power Factor *
*120Vac : *0.99 
*220Vac : *0.96 
*----*

*I* think i can plug 2 parallel of 3 series, i'm near 1500 mA per Led and maybe it's possible to ajust the voltage excedent, right ?


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## FernanDEL (Sep 16, 2009)

I make a mistake 2 parallel of 3 series need (90w 3A 45v)

I have find a Mepos Led driver :
Part Number : ILPA150VU-S052ST
Output Voltage : 52VDC
Max. Output Current : 3.00A
Efficiency (220VAC, Full Load) : 93%
Over Voltage Protection - Min / Typ / Max : 56V / 60V / 63V
Max. Output Power : 150W


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## bshanahan14rulz (Sep 16, 2009)

FernanDEL said:


> the initial question is how to plug 6 ledengin 15w at 1500mA and 15v



assuming you want white. I guess these are in series, as Vf is pretty high.

So, lets say you have the first driver option to work with, and you need to power a total of 9 units? Am I reading you right so far?

Normally with high-power LEDs, it's a good idea not to have LEDs or strings of LEDs paralleled. This is because as they heat up, they draw more current. If one string heats up more than the other that is parallel with it, it draws more current. More current means more heat. More heat means more current. This means the other string starts getting less and less current. Eventually the hotter string will fry from overheating/overdriving.

The bad news: this makes the number of LEDs you can safely drive per driver smaller.

The good news: it's easier to calculate how many LEDs per driver, as they are all to be in series!

Now, if you DO want to try to put two strings paralleled, you will need to make sure that the two strings have the same Vf, same heatsinking. Plus, you will want something to limit current from shifting from one string to the other too much. Usually resistors are used for this, but with the amount of current going through these, your resistor would end up being huge. I'm not really sure of a good way to do this, so perhaps someone else will chime in.

As for running them in one series string, if you ran all 9 LEDs at 1500mA, you would need a driver capable of outputting 135V (9*15V) at 1.5A.
Alternatively, you could get 2 drivers and split them up to lower the total Vf needed.


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## FernanDEL (Sep 17, 2009)

I will pay for simplicity i will go with eldoLED driver, it was my initial decision. ;-)


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## Inkidu (Feb 16, 2010)

Just got 6 (10 watt) deep red (661 nm) and 6 (5 watt) warm whites 

I have on order a meanwell eln-30-24 (1.25 amp, 24 volt) for the warm whites

also on order is a meanwell clg-60-24 (2.5 amp, 24 volt) plan on running 

3 parallel strings of 2 in series. I have seen the precautions of doing so but

there seems not to be a lot choices, that I have found so far, of high volt 

low amp drivers. Will this work? Are there better options? Not a great level 

of experience but I am learning so please make answers on the simple side. 

I got these leds for of all things to grow algae which in turn filters my fish 

tank. I got the warm white leds because they seemed unusual as far as the 

spectrum contain some fairly low blues and some high reds that correspond

nicely with the chlorophyll a absorption spectra. Can anyone show me a link

for how to use a multimeter to check how I should maybe pair them to get 

a similar current running through each string? Do you test when there on or 

off or both. Please be basic I am new to this especially the use of a

multimeter. Are there better driver choices? Any help would be appreciated.

I seem to be able to find a lot more info about the low watt leds. I am 

concerned I might do something wrong and blow up a $30 deep red led or 

worse all 6.


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## purduephotog (Feb 20, 2010)

Inkidu said:


> Just got 6 (10 watt) deep red (661 nm) and 6 (5 watt) warm whites
> 
> I have on order a meanwell eln-30-24 (1.25 amp, 24 volt) for the warm whites
> 
> ...




All I can tell you is I've fried so many ledengin LEDs that I won't run them in parallel anymore.

Magtech makes a couple of higher voltage drivers- the highest I saw is a 48V unit, so that could run 4 dies in series- Ithink they make one at 1A.

I purchased a 48v 1.3A driver and plan to run 14 dies in series, each at 1.3A. Solves alot of problems with the xitanium drivers AND I don't have to get the stupid wires in those little pathetic plugs.


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## Inkidu (Feb 20, 2010)

Thanks for the reply.

Points well taken unfortunately I already ordered the CLG-60-24. So needless

to say I would like to make it work. Would a 1 ohm or possible a 2 ohm give 

enough protection from burning them up? Is that what a resistor would do 

i.e. provide insurance/balance the load? recap 6(10watt deep red) 

typ. 10.8 fVat 833 mA 3p2s 

I don't want to lose efficiency they (meanwell) mention about a Driver IC in the catalog as 

the most efficient, costly, and difficult to hook up. "PWM constant current source

will regulate forward current to achieve even current at each branch" (Driver IC)

It looks like its being used along with the clg-60-24 driver.

What link could I use to find out what and how to use a Driver IC?

Might be beyond someone with little experience. me

But I would like to try.


Thanks for any help.


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## Inkidu (Feb 25, 2010)

If anyone is interested the (6) 10 watt deep reds from LEDENGIN

http://www.ledengin.com/products/10wLZ/LZ4-00R210.pdf

are working 2s3p with the meanwell CLG-60-24 w/o resistors for 5 hours straight 

now. Am I over any possibility of failure?

Thanks for any help.


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## bshanahan14rulz (Feb 25, 2010)

TI has a LED design handbook pdf somewhere with lists of specially designed driver chips. IIRC, some were complicated as stink, but some were "hook up to power, hook up LED, add resistor, voila!"

Never tried getting samples before, though...


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## Bronx68 (May 2, 2011)

We need a 8 to 10 watt heat sink for the LedEngin LZ4 series leds. Anyone know of a good source for these? Mouser has a few but they are all either obsolete or soon to be obsolete.


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## evilc66 (May 3, 2011)

Walk into any PC store. If you need something more specific, you need to tell us.


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## Bronx68 (May 3, 2011)

Yes we are using a heat sink made by CoolerMaster part number ECC-00500-01GP. It is 35mm x 105mm and has special mounting for LedEngin (the manufacturers name) mcpcb boards. Three hole mounting. It has a thermal resistance of 7.12 deg C / watt.**


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## David_Campen (Aug 28, 2011)

I have several LedEngin LZ4-40R100 623 nm emitters on order with Mouser. These have the 4 dies connected serially on an star mcpcb. Mouser also has heat sinks available for this package:
http://www.mouser.com/Thermal-Management/Heatsinks/_/N-5gg0?P=1yztium
I will be using the Ohmite 76 mm heat sinks:
http://www.mouser.com/ohmiteheatsinks/
and a Magtech L07U-700 driver:
http://www.ledsupply.com/l07u-700.php
These will be for growlights for orchids. I would have liked to use the LedEngin LZ4-40R200 660 nm emitters but neither Mouser or Newark has these as stock items. To buy the LZ4-40R200 from Mouser you have to order a lot of 70. Newark only requires an order for 10, so whenever they get these in stock I will order a lot of 10.


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## blasterman (Aug 29, 2011)

I'm not convinced of the need for 660nm given this wavelength is almost non existent in other artifical sources, but that's a separate arguement. 

LEDsupply has triple-up Rebels here at 660nm. Might be worth looking at given the inefficiency of LEDEngin.

When I rolled the prices for triple Cree and Rebel stars they were cheaper per lumen than LEDEngin as well.


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## David_Campen (Aug 30, 2011)

blasterman said:


> I'm not convinced of the need for 660nm given this wavelength is almost non existent in other artifical sources, but that's a separate arguement.


Yes, after doing some research today I've decided that 625nm will do as well or better than 660.


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## blasterman (Aug 30, 2011)

Also, I'm not trying to distract from the LEDEngin discussion. 

For plant lights the die-size / optic issue you encounter with flashlights typically isn't an issue, and so I tend to focus strictly on the absolute performance numbers of the platform - brand aside. In this respect triple Rebels and Crees are becoming increasingly easier to find.


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## xul (Aug 30, 2011)

HarryN said:


> - The extremely low thermal resistance - about 1/2 of many packages


Means you can use it at a higher ambient, or put twice the watts in, or have a longer service lifetime, other things being equal.
http://en.wikipedia.org/wiki/Thermal_resistance_in_electronics
http://lightingresearch.org/programs/solidstate/pdf/guSPIE.pdf


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## David_Campen (Nov 6, 2011)

I just had a failure in a string of LZ4-4 LEDs. There are 4 LZ4-4 in the string - an LZ4-40WW00 in parallel with an LZ4-40B200 and that in series with an LZ4-R100 and an LZ4-R200. These were being driven by an LP1040-36-C-1050 constant current driver (High Perfection Tech). They were suitably heat sinked with the star MCPCB boards screwed onto 1/8" thick copper and with 2 3" long extruded aluminum heat sinks attached to the copper, thermal paste was used. The copper and the aluminum heat sinks did not seem to be getting above 130F.

I put this assembly up on a ceiling and had run it for several days at about 8 hours per day. Today 3 of the 4 LEDs went out with only the LZ4-R200 remaining lit. I haven't yet taken the assembly down from the ceiling for examination but since the LZ4-R200 remained lit it seems that the others shorted.

Does anyone have any similar experiences or ideas as to what happened/why?


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## Illum (Nov 6, 2011)




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## saabluster (Nov 7, 2011)

Illum I noticed you edited your post so we will just pretend this never happened.


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## David_Campen (Nov 8, 2011)

I found my short, it was from poor assembly on my part, one of the DC power leads in one of the LED modules had managed to short to the case.


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## Illum (Nov 8, 2011)

saabluster said:


> Illum I noticed you edited your post so we will just pretend this never happened.



I honestly did not bother to check the date of this thread


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## thepaan (Nov 9, 2011)

blasterman said:


> I'm not convinced of the need for 660nm given this wavelength is almost non existent in other artifical sources, but that's a separate arguement.



The peak absorption in terms of efficiency is between 650 and 670. The absence of those wavelengths in artificial sources is due to the fact that artifical lighting is primarily developed for people, who percieve light much differently than plants. The wavelength is only important when concerning efficiency, but then, that is the whole point of using an LED instead of, say, a halogen. There are many factors that go into the efficiency of the light fixture, so, in the end, a 660 nm LED lamp may only be about 10-20% more efficient (in terms of growth per unit of grid power) than something like an HPS. The larger initial price of LEDs increases the total cost of ownership which may not be recovered, depending on how long you use the lamp.

More important than wavelength, in horticultural lighting, is the amount of light. This is because given enough inefficient light, the same amount of growth can be achieved as efficient light. Just be sure that, if using LEDs, you mix at least some blue ones in with the red. Generally, with any light you choose, Daily Light Integral (DLI) can be calculated while ignoring the efficiency. DLI is a combination of intensity and duration measured over the course of a day. Most plants need between 10-20 moles/day, but I hear Orchids vary widely between species. The American Orchid Society recommends optimum intensities for certain species, such as Phalaenopsis and Paphiopedilum at 1500 foot-candles (fc), Miltoniopsis and Zygopetalum at 2500 fc, Cattleya at 3000 fc, and Brassia, Cymbidium, Degarmoara, Dendrobium and Oncidium at 5000 fc, for a minimum of 6 hours a day. This comes out to about 4, 7, 8, and 14 moles/day, respectively.

Personally, I enjoyed using the LEDEngin emitters. I am only sad that they discontinued production of the 15W deep reds.


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## Rina (Oct 9, 2015)

Hi, 
I found this model online, sort of pyramid design, creative solutions possible,
https://documents.mrosupply.com/product_documents/21/21120502004/pd2100masi_eng.pdf


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