DIY COB LED Calculator
- Thread starter bggrass
- Start date
coreywebster
Well-Known Member
oh dear, where did all my lovely efficiency go to.. If these calculations are correct I have just lost 8-10%. I thought they were more efficient than Cree. Down to 42% @ 1400mA, seems that's the difference between 90cri and 80 cri. The 90s are 42.39%
Sheeeet
Sheeeet
bggrass
Well-Known Member
I just looked at the error he gets, it's definitely an outdated java version.
There is no decimal point when you enter amps. It takes the value in miliamps mA.
coreywebster
Well-Known Member
Weird, works for me, although I wish I had never seen the results. Talk about burst bubble
bggrass
Well-Known Member
I don't know what the problem is then... Did you restart after the update?
Anyone else has the same problem?
bggrass
Well-Known Member
I would take the cree estimates with a grain of salt. When I tried to pull out the formulas for cree, on their cree pct tool, the lumens that I got were about 20 lumens per watt lower. Check it out for yourself for the cree cob you are looking at and you'll see that the lm/w on the efficiency spreadsheets and the ones on the website are different. I'm not sure how Supra pulled those numbers back then or what he accounted for... Just by looking at the difference, cree and citizen are probably very close in efficiency. We are using different data when comparing...
bggrass
Well-Known Member
Look at the lumens per watt of the cobs you are comparing on the cree tool and the citizen at the same Tj and amperage. If the lumens per watt are close on both, then they are supposedly equivalent... supposedly
If we run them through the same formulas they should output an equivalent result.
If we run them through the same formulas they should output an equivalent result.
captainmorgan
Well-Known Member
53% efficient, 4 COBs per driver at 142 v with HLG240H-C1750
muleface
Well-Known Member
how did you get that number? also, do you have any suggestions for running 12 of these COBs? a different driver or is the one I am talking about a good choice? thanks for your quick response.
verticalgrow
Well-Known Member
400w driver @1050ma will run 11 3590 cobs, $100usd
http://www.cutter.com.au/proddetail.php?prod=cut2999
VG
ruwtz
Well-Known Member
Driver efficiency rating, specific to your chosen driver.
Meanwells are something like 94 or 96% efficient, can't remember which.
This caught me out too.
linky
Well-Known Member
Ahh okay, thank you
i had the same problem , i played around my localisation settings changed from french canadian to english united states in region format setting and citicalc works now
mr. Amsterdam
Well-Known Member
Yes i also need help, i have this same problem with Java 102 update.
bggrass
Well-Known Member
Sorry I don't have a solution. Seems to be some single cases and it seems to happen to users outside US. It's beyond my knowledge. Someone posted earlier that they had to change their settings and language on their OS. I'm not sure how that gets connected. Try running it on your phone...
I thought you were wondering what number to put in the Tj field. For the most part, people around here use 50, as in 50*C.
coreywebster
Well-Known Member
Are you using the link in the sig from the post above yours? Do you have java installed and up to date?