CobKits
Well-Known Member
boy thats tight id have to test it. it wants 156V and has 152
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linky
Well-Known Member
Okay let me know, ready to buy!
If you have any other configurations that would be similar I am open to that as well. I am just looking for a little better light coverage, having 3 bars with 2 cobs each over the 5 x 9 instead of just 4 cobs total for that space. thanks again!Hello cobkits,
I'm thinking of getting started with 3 1825 3500K 90cri run at 80 watts each. My understanding is that they must be run in parallel as the holder is not rated for series voltage, correct ?
Which driver do I need HLG-240H-48A or 54A ? Looks like the 48V is just short, but how does the dimming work with the 54A ?? Are there any risk of killing the cobs ?
I'm not sure I understand dimming on CV models, is it linear like on CC drivers ?
What would be the current range ??
Thanks.
I'm thinking of getting started with 3 1825 3500K 90cri run at 80 watts each. My understanding is that they must be run in parallel as the holder is not rated for series voltage, correct ?
Which driver do I need HLG-240H-48A or 54A ? Looks like the 48V is just short, but how does the dimming work with the 54A ?? Are there any risk of killing the cobs ?
I'm not sure I understand dimming on CV models, is it linear like on CC drivers ?
What would be the current range ??
Thanks.
CobKits
Well-Known Member
with 3 youre right about 150V which is doable. ive personally run 4 in series on a 320-1400 without issue which worked fine for me.
you can run 3 on a hlg185h-48A at 75W ea. a hlg240h-48a (which i dont stock) would prob run them up close to 100W ea
dimming is the same with CC and CV drivers, there are A and B models for both. if you want to run 1825 on a 48V CV driver you need the A model, and its a great match, uses all of the driver with 2 or more cobs on it .
How many watts of this cobs will be equal of a 1k of hps light bulb?
Thanks in advance.
Hi again,
Not that I don't trust you, but the datasheet of hlg-185h-48A says its maximum is 187.2W, how could it run 3x75w=225w ??
Did you notice the ùax voltage on the 240 is only 51.2V ? ... and same question, how can a 240h run 3x100W when it is rated at max 240W ??
Wouldn't a 54A version be more apropriate ?
Do you make discounts o=for light engines if bought in numbrrs ? (21 ?)
Thanks
Not that I don't trust you, but the datasheet of hlg-185h-48A says its maximum is 187.2W, how could it run 3x75w=225w ??
Did you notice the ùax voltage on the 240 is only 51.2V ? ... and same question, how can a 240h run 3x100W when it is rated at max 240W ??
Wouldn't a 54A version be more apropriate ?
Do you make discounts o=for light engines if bought in numbrrs ? (21 ?)
Thanks
CobKits
Well-Known Member
look at the test report not the datasheet for real-world numbers
im not sure what driver you are referring to by "the 240". that could mean a dozen different models
i have some room on those as a lot of light engines is labor, its easier to sit down and make a bunch at once
Sorry, I meant the HLG-240h-48A...
edit : found it ! Where can I find those test reports please ?
edit : found it ! Where can I find those test reports please ?
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CobKits
Well-Known Member
meanwell site. they dont allow hot linking but if you go to the datasheet and click on "REPORT" on top menu bar for 48V you'll see:
52.7V x 5.4A = ~285W
note that the max voltage is considerably lower than the 185's 53.5V max
which means you can only run 1825s to ~1800-1900 mA as aooposed to 2100-2200 with a 185.
you can use a 54V driver but will lose current and yield less wattage overall
52.7V x 5.4A = ~285W
note that the max voltage is considerably lower than the 185's 53.5V max
which means you can only run 1825s to ~1800-1900 mA as aooposed to 2100-2200 with a 185.
you can use a 54V driver but will lose current and yield less wattage overall
EfficientWatt
Well-Known Member
Hi bobby,
I'm trying to catch up on the citizen "trend", and trying to debunk the data around. Can't seem to find enough of it but ..
... I don't mean to be rude or crash the party, but your best guesses seem well off to me ... just trying to get an accurate idea of the performance vs CREE.
Using the 1818 guess and comparing to datasheet at nominal current, you are basically saying the 4000K 80cri spectrum has an LER of 271 ...
Doesn't that sound way off to you ?
Has anyone calculated LER for any of the citizen by integrating the curve ?
Again, not trying to troll, trying to get the true story
EDIT : @alesh says here http://rollitup.org/t/cob-manufacturers-other-than-cree-or-bridgelux.883644/page-6#post-12104632
he expects 4000K 80cri to have an LER of 355, which would give an efficiency of 40% at nominal current vs your 53%. That's 30% more light in your guess than his (!)
I'm trying to catch up on the citizen "trend", and trying to debunk the data around. Can't seem to find enough of it but ..
... I don't mean to be rude or crash the party, but your best guesses seem well off to me ... just trying to get an accurate idea of the performance vs CREE.
Using the 1818 guess and comparing to datasheet at nominal current, you are basically saying the 4000K 80cri spectrum has an LER of 271 ...
Doesn't that sound way off to you ?
Has anyone calculated LER for any of the citizen by integrating the curve ?
Again, not trying to troll, trying to get the true story
EDIT : @alesh says here http://rollitup.org/t/cob-manufacturers-other-than-cree-or-bridgelux.883644/page-6#post-12104632
he expects 4000K 80cri to have an LER of 355, which would give an efficiency of 40% at nominal current vs your 53%. That's 30% more light in your guess than his (!)
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CobKits
Well-Known Member
yes @JorgeGonzales has done it, 338 for 4000K. his numbers agreed with some of the LERs that @robincnn got from citizen
https://www.rollitup.org/t/cheap-and-cheerful-diy-using-citizen-cobs.909460/page-13#post-12802292
in fact scroll up on that page and you'll see that @tomate got similar results. whole page has some good discussion
https://www.rollitup.org/t/cheap-and-cheerful-diy-using-citizen-cobs.909460/page-13#post-12802292
in fact scroll up on that page and you'll see that @tomate got similar results. whole page has some good discussion
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CobKits
Well-Known Member
heres some spot measurements (12" on axis, no optics) for a variety of cobs
https://www.rollitup.org/t/why-are-cobs-better-and-whats-so-great-about-the-3590.920480/#post-12944216
will retest in this fashion once i get the sphere up and rolling, i have some orders i have to clear out first
https://www.rollitup.org/t/why-are-cobs-better-and-whats-so-great-about-the-3590.920480/#post-12944216
will retest in this fashion once i get the sphere up and rolling, i have some orders i have to clear out first
EfficientWatt
Well-Known Member
Ok
Well then 1818 @84W 4000K 80cri ( 1.62A and 52V using LER 338 ) has:
Minimum efficiency Tj@85° = 31.9% 37.9%
Typical efficiency Tj@85° = 36.2% 43%
Typical efficienc Tc@25° = 39.6% 47%
EDIT : I made a mistake, correct efficiency in blue
Vs 53.45% (?)
Did I miss something because that's like way, way off .. ?
Well then 1818 @84W 4000K 80cri ( 1.62A and 52V using LER 338 ) has:
Minimum efficiency Tj@85° = 31.9% 37.9%
Typical efficiency Tj@85° = 36.2% 43%
Typical efficienc Tc@25° = 39.6% 47%
EDIT : I made a mistake, correct efficiency in blue
Vs 53.45% (?)
Did I miss something because that's like way, way off .. ?
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Olive Drab Green
Well-Known Member
How does any COB have less than 50% efficiency? Where'd you get your numbers? I was pretty sure Bridgelux's Vero, Cree's CXB series, and Citizen 1818s were all in the same echelon, although now Vero's pulling ahead of Cree, who hasn't put any new generation of emitters out lately.
CobKits
Well-Known Member
run it hard...
Olive Drab Green
Well-Known Member
I suppose, but at 84w? My fixtures are run pretty hard and don't dip below 50%. 85w (92w including fan and such) of light for the Vero, 78w (89w including the fan and such) for the Cree.
I dunno the voltage of the Vero which is run at 1670mA, but the Cree is 36v @ 2150mA.
CobKits
Well-Known Member
heres citi calc at 4000k 80cri, 85C Tj:
42.8% efficient but that Tj is way high for 84W. 45% is more realistic.
and the citis seem to outperform the datasheets in practice. in my testing the 1818 at 84W was about as efficient as cxb@ 67W. pct says thats about 153 lm/W or 47% efficient on a 323 LER for 4000k 70 cri cree
question remains would you rather have a higher efficiency number if the LER is lower? or would you rather have straight lumens (/PAR)
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