New COB from Cree 180Watt Alum based

CobKits

CobKits

Well-Known Member
at least 5 different manufacturers make 28mm and 38mm cobs that use the same holders and run at similar voltages
 
welight

welight

Well-Known Member
yep but I can give you another 5 that dont, suffice to say that Cree will release 2 new series before year end and one will be based around your noted 5
 
PilouPilou

PilouPilou

Well-Known Member
Hi Mark!

Done!... great news! I f you can make an efficiency chart with that new cob it's more than perfect!! :)
 
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CobKits

CobKits

Well-Known Member
it appears so- I've observed that CXBs have a slightly steeper curve on a graph of efficacy vs power. Some people say thats excellent low current performance. I've always considered it as poor thermal dissipation at high currents.

Keep in mind a cxb3590 only has 144 dies... thats the same as a citi 1212. Cree does have great blue dies, if they can put more dies per chip and also increase thermal performance they may regain the lead in the industry. but its a moving target. bridgelux, citizen and luminus are all coming up on a year on their latest generation of chips. I've been told citi gen 7 is slated for Q2/Q3 2018, im sure the others are on a similar schedule
 
K

kony brado

Well-Known Member
CobKits said:
it appears so- I've observed that CXBs have a slightly steeper curve on a graph of efficacy vs power. Some people say thats excellent low current performance. I've always considered it as poor thermal dissipation at high currents.

Keep in mind a cxb3590 only has 144 dies... thats the same as a citi 1212. Cree does have great blue dies, if they can put more dies per chip and also increase thermal performance they may regain the lead in the industry. but its a moving target. bridgelux, citizen and luminus are all coming up on a year on their latest generation of chips. I've been told citi gen 7 is slated for Q2/Q3 2018, im sure the others are on a similar schedule
Click to expand...
Maybe the ceramic has a role in electric insulation between the cob and sink for safety purpus ?
Is copper to expensive to use? If so than silver gold and diamond are out of consideration.maybe zircon ? :lol:

The 1 mm copper pcb(f strips) at 0.0583 is getting to 50c and both sides of the pcb are the same temp exactly.
im really impress with the samsung pcb.
thank's
 
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P

Photon Flinger

Well-Known Member
Vero 29 C are 0.04 c/W delta between case and junction which gives you a good idea roughly what the efficiency is through heat generation. Lower the number, the less heat generated that needs to be sinked.

@117w, Vero 29c is roughly a 5c delta at a stable ambient. @46w it is only 2c. @23w 1c.

No need for bulky heat sinks if run low. Same as QBs.
 
K

kony brado

Well-Known Member
Photon Flinger said:
Vero 29 C are 0.04 c/W delta between case and junction which gives you a good idea roughly what the efficiency is through heat generation. Lower the number, the less heat generated that needs to be sinked.

@117w, Vero 29c is roughly a 5c delta at a stable ambient. @46w it is only 2c. @23w 1c.

No need for bulky heat sinks if run low. Same as QBs.
Click to expand...
great info
what is the calculation and where is the data from if i may ask(i don't remember this from data sheet)
thank's :peace::peace::peace:
 
ANC

ANC

Well-Known Member
Have you tried lapping a Vero yet? Friends assembled the units I'm using so I never got to lap them like I do with CPUs.
Makes it a bitch to remove afterward. Capillary suction is a bitch.

You glue some sanding paper to a mirror and flatten the mating surfaces of the heatsink and the thing you want to cool. You need virtually no thermal compound to stick things together afterward.
 
P

Photon Flinger

Well-Known Member
ANC said:
Have you tried lapping a Vero yet? Friends assembled the units I'm using so I never got to lap them like I do with CPUs.
Makes it a bitch to remove afterward. Capillary suction is a bitch.
Click to expand...

Completely unnecessary.

LEDs will put out a constant heat once stabilized and don't spike up and down like CPUs do.

You could probably mount Vero 29s with bubble gum.

Learn to twist :)
 
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