Evil-Mobo
Well-Known Member
What would the numbers look like for the 1812's @1050mah?
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CobKits
Well-Known Member
a little less efficient than the 1818s, Which makes sense if you understand that an 1812 are 18 dies in series and 12 in parallel. the same current running thru an 1818 (18 in series with 18 in parallel) would be more efficient (same voltage per string, less current per die)
from citi tool (conservative but good for relative comparisons):
from citi tool (conservative but good for relative comparisons):
Evil-Mobo
Well-Known Member
TY for the prompt reply.
PhotonFUD
Well-Known Member
Well considering his commercial offering (PLC) is no longer doing business it is understandable that he tries to defend his position. His videos speak volumes about how 'well' he grows. If that is what you are looking for, then by all means follow his path. That is the great thing about hobbies, you get to to pick what you want to do. What is right for you might not be for someone else.
In order to get empirical evidence, as has been asked, there has to enough time given to get meaningful data. And there is nothing wrong with asking for empirical evidence especially if you are a commercial operation. Both the research and hobby areas of horticulture provide the proving grounds for new technology.
So far Cobkits has been more than helpful with providing very useful data. That data is great for planning. Sure it might not be exactly real world, but it is within tolerable error and therefore provides a good guide.
I had done some research into using citizen prior to joining this forum and was looking for the cheapest available. Cobkits with the $13.25 1212s didn't seem realistic so I took an interest to these discussions. Glad I did or else i wouldn't know that there is an expected price drop happening.
PhotonFUD
Well-Known Member
As I had read, an anticipated price drop of current models when they release next versions.
CobKits
Well-Known Member
well its pretty constantly dropping. crees were north of $50 last year and are now upper 30s/low 40s. were assuming 3590s will drop in price when the new models come out but nobody knows when that is and cree just had a substantial drop in price last month
citis are stable but new ones due in january, hard to say what will happen with that
new veros are coming out at old vero pricing so theres no reason youd buy an old vero but they might blow out old stock at $15 or something
citis are stable but new ones due in january, hard to say what will happen with that
new veros are coming out at old vero pricing so theres no reason youd buy an old vero but they might blow out old stock at $15 or something
CobKits
Well-Known Member
here was a low-current test i did with more data points when i got my better power supply a month ago
PhotonFUD
Well-Known Member
It was more of a general statement. As in I wouldn't know if there was a price drop forthcoming if it wasn't for the discussions. I started with Digikey at ~24/unit, then yours at 13.25/unit and now you have a 10% discount code making them ~11/unit. For my perspective that is a price drop attributed to the forum.
GrowUrOwnDank
Well-Known Member
Cree fans are like apple's fans. Don't get along well with Vero and Citizen fans.
Cant wait for the Citizen 3500k 90 cri grow to finish
https://www.rollitup.org/t/northern-grow-lights-photon-180-clu1825-grow.915159/page-2#post-12949577
@sixstring2112 you need to quit the Cree cult and join Vero 29 Gen 7 or Citizen clan. That's whats going on your SST X
Damn this is a tough crowd lol.Their Called CCS Which Stands For Cree Cob Snobs And They Lack Imagination And They Are A Monkey See Monkey Do Type of Grower. They Are Also The Type Of Ppl Likely To Walk Off A Cliff While Taking A Selfie Just Saying If The Truth Hurts Then Don't Fool Yourself Cause Its Winking At You
weed-whacker
Well-Known Member
yeah that's what has me suspicious too, I am comparing using 6 of the 12 12 vs 3 of the cxb3590 both at 150w total
your data suggests efficiency of about 50% for the 1212 @ 25w
and @CobKits spread suggests around 59%
vs cxb @ about 56%
CobKits
Well-Known Member
it is 100% relative to cree which is why i always try to mention it as an "approximate, estimated, or relative" efficiency. There was a discussion recently where someone said that cree PCT was actually accurate to "the spreadsheet" within a fraction of a percent. In reality either cree is overreporting lm/W or citi is underreporting lm/W as their data doesnt jive. people are obsessed with their efficiency numbers but in reality if cob A is consistently brighter than cob B at a given wattage, are you going to use the real-world testing data or what the manufacturer told you?
Those mfr-provided tools are great for comparing various intra-manufacturer models and setups but clearly there is a bias when compared with other manufacturer's data
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CobKits
Well-Known Member
the only thing i could do to make it more 'real world' is put a plant under the sensor, its an actual light output test of an actual chip on a real heatsink. open to ideas on how to improve the methodology. not perfect but for example i was able to run 5 different getian models and pick the one or two i might be interested in stocking which is 100% based on their performance and cost relative to the others.
CobKits
Well-Known Member
PCT says for CXB DB bin at 1.4A (48.77W) Tc 25C you will get 9094.6 lm x 3 = 27283 lm @ 186.5 lm/W
citi tool says for 1212 4000k 80 cri at Tc 25C, 700mA (24.2W) you will get 4208 lm x 6 = 25248 lm@ 174 lm/W
my spot tests say that cree@ 1.4A = 435 umol/49.35W = 8.815 umol/W
1212@ 0.7A = 226 umol/23.89W = 9.460 umol/W
mfr data has CXB@7% more efficient under those conditions
real world testing has 1212 @ 7% more efficient under those conditions
i cant call it a fluke when citi beats cree at 3000K, 4000K, 5000K.... how many more chips should i test? heres an old 3000K test. both are 80 cri here. again lets look at PCT vs citi tool
PCT:CB bin: 1.4A: 8395 lm/W @ 48.77W = 172.1 lm/W
citi tool:3000k 80 cri: 4082 lm @ 24.2W = 169 lm/W
advantage: cree by 1.8%
my measurements
CB bin@ 1.4A = 386 umol @ 47.88W = 8.06 umol/W
1212 3000k 80 cri @ 0.7A = 206.6 @ 23.73W = 8.71 umol/W
advantage: citi by 8.1%
CobKits
Well-Known Member
i could also calc out bridgelux vs cree or citi using their tool vs online measurements etc but as you can see number crunching gets very intensive. id rather just take the measurements i have and present them with that big ass grain of salt....ill provide raw data to anybody who wants to do whatever they wish with it
ya bongo
Well-Known Member
49.35W in the spot?
no light outside the spot?
Rocket Soul
Well-Known Member
Hey Cobby. In another thread u posted tests of a few Getian led cobs, gt3838, ct2828 and gt2828. What where the forward voltage on these units cause they look very interesting pricewise? And what was ur general impresion? Will either of these chips fit with easyto source holders and optics?