COB efficiency Spreadsheets
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captainmorgan
Well-Known Member
I've scrogged with as little as 530 PPFD and got great results.
Best to start a thread of your own for questions so we don't clutter up others.
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HighOnDIYLife
Active Member
Any spreadsheets available on those citizens COBs? (especially CLU048-1212 3500K?)
Hi .. I would like to contribute little things, which can save some time in decision making and planning structures grossed DIY LED panel .. unfortunately I did not include CreeCXB2530.. Although now Cutter. com.au is fantastic the money mostly in high 3000K version 90CRI .. I think that the excellent choice ..s even better range and a heavy competitor for 18 vero .. Now a very interesting choice of chips from Citizen ver.5
Greengenes707
Well-Known Member
https://www.cdiweb.com/datasheets/citizen/CITILED-ver5-Selection-Tool.xlsx
It won't hyperlink the whole link...copy and paste the whole link above into your browser. It's in excel, also works on mac numbers.
I'm not totally sure how to change CCT. I'm sure someone else does.
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JorgeGonzales
Well-Known Member
Worth mentioning that it only works fully on the latest version of Excel, otherwise you have to make do without the dropdown menus. It also won't supply Supra-style efficiency based on LER or more importantly umol/J, but I guess we have all the info at this point to do that. What we don't have is Supra's current and temp droop data, unfortunately. That's what's great about his sheets.
To run in Excel online, I had to edit the metadata to remove worksheet protection, there is a copy of that and discussion here: https://www.rollitup.org/t/is-this-a-vero-29-killer.906620/page-3#post-12620863
A nice key from @guod here:
To run in Excel online, I had to edit the metadata to remove worksheet protection, there is a copy of that and discussion here: https://www.rollitup.org/t/is-this-a-vero-29-killer.906620/page-3#post-12620863
A nice key from @guod here:
JorgeGonzales
Well-Known Member
Sure, but we have that information from the manufacturer, numbers which are likely accurate at the minimum and possibly conservative, if Cree and Bridgelux are any indication.
Still do not understand the difference between Tj and Tc compared light power between the various different manufacturers .. COB Cree, Bridgelux, Citizen
.. Datasheet BRIDGELUX noted that Tj = Tc and outputs are listed lm to 25 ° C and 85 ° C .. how to reach the same Tj = Tc? Tc is the temperature spread of heat to the pad COB while Tj temperature should be directly on the chips (junction diodes with the pad?) Is that the measurement point is at VERO in close proximity of the chip, unlike Citizen, where the measuring point in another, more distant point? .. I'm in this nice mess .. U can see Citizen linear temperature shift between Tc and Tj
... Tj always increases linearly with increasing TC
So rely on what, how to compare? Bridgelux if Tj =TC the same, is not so important, but at the Citizen for comparison determining Tc or Tj .. by Cree I read that unite Tj at 85 ° C for all models, while it should be the max. operating TC, so even a Cree Tj = Tc? After all, each model COB has different thermal properties (thermal resistance, etc.) and light output should determine the temperature of the chip Tj .. why is it in Cree, Bridgelux Tj = Tc? .. it is thus in fact an reality heat so perfectly spread over pad, they are the same temperature as the chip mat? .. or the whole understand wrong?
.. Datasheet BRIDGELUX noted that Tj = Tc and outputs are listed lm to 25 ° C and 85 ° C .. how to reach the same Tj = Tc? Tc is the temperature spread of heat to the pad COB while Tj temperature should be directly on the chips (junction diodes with the pad?) Is that the measurement point is at VERO in close proximity of the chip, unlike Citizen, where the measuring point in another, more distant point? .. I'm in this nice mess .. U can see Citizen linear temperature shift between Tc and Tj
... Tj always increases linearly with increasing TC
So rely on what, how to compare? Bridgelux if Tj =TC the same, is not so important, but at the Citizen for comparison determining Tc or Tj .. by Cree I read that unite Tj at 85 ° C for all models, while it should be the max. operating TC, so even a Cree Tj = Tc? After all, each model COB has different thermal properties (thermal resistance, etc.) and light output should determine the temperature of the chip Tj .. why is it in Cree, Bridgelux Tj = Tc? .. it is thus in fact an reality heat so perfectly spread over pad, they are the same temperature as the chip mat? .. or the whole understand wrong?
SilvioBerlusconi
Active Member
How you get Tj = Tc:
You place your LED on a huge block of copper, which you can cool/heat to the desired temperature. Then you send a quick pulse (like 10ms) of energy into the LED and measure the output.
You place your LED on a huge block of copper, which you can cool/heat to the desired temperature. Then you send a quick pulse (like 10ms) of energy into the LED and measure the output.
So that essentially means that determines only in laboratory conditions, not real? to avoid distort the figures of the light output was between Tj and Tc? for this reason can be Tj = Tc? And what does it mean for real, real application in practice? .. It means that datasheet simplification, those lumens of light output at Tj = Tc 25 ° C are totally unrealistic .. therefore better basis for comparison using Tj 85 ° C .. how to calculate on paper rather than measurement in real Tc? .. So how do you compare with chips Citizen .. set in the configurator Tj 85 ° C should give accurate and truthful performance comparison between the Cree, Bridgelux, Citizen? .. Very THX
If it really .. for Citizen CLU48_1212 example. 3500k 80CRi very proficient superior opponent vs. CXB3070 3500k 80CRi BB .. almost the same performance and efficiency in the soft run amps and hard running a little better for Citizen .. in that case more beneficial purchase price - output ratio?
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ttystikk
Well-Known Member
Lol @ unrealistic
JorgeGonzales
Well-Known Member
I have to say, the measurements Bridgelux uses for lm/W is pretty goofy. Just don't try to explain fair comparisons in the all things Vero thread. Trust me on this one.
What does it sound so funny? .. I get to learn and take advice .. if this is the case ..thx
JorgeGonzales
Well-Known Member
Duh. Although since you are in this thread, you probably want to look at SupraSPL's spreadsheets, and search and read about them. The CXB3070 is likely quite a bit ahead at lower currents.
[Quote = "JorgeGonzales, příspěvek: 12684423, Nápověda člen: 929368"] Duh. I když od té doby jste v tomto vlákně, pravděpodobně budete chtít podívat na SupraSPL je tabulek a vyhledávat a číst o nich. CXB3070 je pravděpodobné, že docela dost napřed při nižších proudech. [/ Citát]
.. Ano .. Věřím supraSPL kde je chyba? konfigurátor Cree PCT nebo Cititzen? .. V jaké hodnoty na grafu je na supraSPL .. Tj nebo TC50 ° C
Teď, co mě zajímá a mají zájem o pravdu .. možné spravedlivě srovnat světelný výstup Cree, BRIDGELUX, občan .. Je-li u Cree a BRIDGELUX laboratorní hodnoty dává TJ = Tc
.. Ano .. Věřím supraSPL kde je chyba? konfigurátor Cree PCT nebo Cititzen? .. V jaké hodnoty na grafu je na supraSPL .. Tj nebo TC50 ° C
Teď, co mě zajímá a mají zájem o pravdu .. možné spravedlivě srovnat světelný výstup Cree, BRIDGELUX, občan .. Je-li u Cree a BRIDGELUX laboratorní hodnoty dává TJ = Tc
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ttystikk
Well-Known Member
Never assume that something can't be done.
sorry .. between us seemed too much the language barrier .. not to understand that if I use through translator
I know they say that nothing is impossible, therefore everything is possible and can be achieved Tj = Tc
but it is beyond reality too