New Vero Cob?
- Thread starter WoodyWoodWood
- Start date
Hey, could you tell me the heat transfer plate measurements on the back of the COB? I was thinking around 38x38mm but wasnt sure and couldnt find anything.
robincnn
Well-Known Member
around 31.6x31.6mm
Thank you very much for that info!
Rahz
Well-Known Member
So what do you make of the LPW numbers being the same with same size LES and multiple wattages?
JorgeGonzales
Well-Known Member
I think the answer might be in the picture. Regardless of what voltage those two are, the die pattern is different.
Is that right @robincnn? Does one of them have more LEDs?
Doesnt it have to do with the differences in die patterns? Or is there something inherently more efficient about running more voltage through a COB rather than pumping more current through it? Just spitballin here.
Rahz
Well-Known Member
Could be die pattern, but I'm skeptical of the numbers. If they have a die pattern that gives them 161 LPW at 120 watts then I would expect better performance in the 80 watt version unless they are saving a buck using old technology in the lower wattage chips. It's a mystery that needs to be tested.
JorgeGonzales
Well-Known Member
If I understand you correctly, isnt the answer simply "more leds run at less current in the same LES size"?
Youre referring to the different voltage versions, not wattage. Correct? Also, maybe the pattern is designed to run at a higher voltage wont necessarily work as well in a lower voltage situation. The fact is ~70v+ COBs really limit the available driver opportunities compared to even the ~50v version. Efficiency trade off for having a much wider array of available drivers.
Rahz
Well-Known Member
Sure, voltage and current are different, but that doesn't change the fact that one is using 150% the power of the other. It doesn't make sense especially when you consider the LPW for both is exactly 161. I want to see some spot testing to confirm the numbers.
JorgeGonzales
Well-Known Member
There are some obvious mistakes in the data sheet, but that would be a doozy.
robincnn
Well-Known Member
The Gen 6 vero has bigger diodes and not as many. was easier to count. I cannot count on the new veros. Dies are much smaller and more.
The 52v version has longer straight led to led connections.
The 37v vero has long straight led to led connections in center but has more zig-zag led to led connections.
37V is more like honeycomb
52 more like
I think the straight led arrangement and less zig-zag connections in 52V allow it to pack more diodes than the 37V Vero.
That is why the 52V has same lm/w as 37V
Will try out the 70V version too. I am curious to see how the leds are packed
@Rahz @JorgeGonzales
Anyone wants to count
The 52v version has longer straight led to led connections.
The 37v vero has long straight led to led connections in center but has more zig-zag led to led connections.
37V is more like honeycomb
52 more like
I think the straight led arrangement and less zig-zag connections in 52V allow it to pack more diodes than the 37V Vero.
That is why the 52V has same lm/w as 37V
Will try out the 70V version too. I am curious to see how the leds are packed
@Rahz @JorgeGonzales
Anyone wants to count
Stephenj37826
Well-Known Member
I came up with 472,324.275. Should I recount?The Gen 6 vero has bigger diodes and not as many. was easier to count. I cannot count on the new veros. Dies are much smaller and more.
The 52v version has longer straight led to led connections.
The 37v vero has long straight led to led connections in center but has more zig-zag led to led connections.
37V is more like honeycomb
View attachment 3770810
52 more like
View attachment 3770811
I think the straight led arrangement and less zig-zag connections in 52V allow it to pack more diodes than the 37V Vero.
That is why the 52V has same lm/w as 37V
View attachment 3770817
Will try out the 70V version too. I am curious to see how the leds are packed
@Rahz @JorgeGonzales
View attachment 3770805
Anyone wants to count
View attachment 3770814
View attachment 3770815
freezypops
New Member
i also think the 29 C datasheet is not accurate in the excel file. Eagerly awaiting real test data. Thank you to all testing
guod
Well-Known Member
lm/W is set by the single die on the COB, and in the Datasheet the Temperature is fixed (25°C / 85°C)
PicklesRus
Well-Known Member
Hey I'm going to sound like a total noob by asking this, (I promise it's related to all of this) but I'm looking at some Vero 13 Gen7 cobs and I'm trying to figure out how much heatsink I need.
I went through the old posts to figure out how to calculate efficiency and I am at the point of extracting the numbers from the SPD graph and saw some of those comments here. That is a little over my head - at this point I kind of just want to run these passively and don't want to buy too much heatsink if it's unnecessary.
http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=BXRC35E2000D73BRIDGELUX4073511&IM=0
Can someone point me back on track please?
I went through the old posts to figure out how to calculate efficiency and I am at the point of extracting the numbers from the SPD graph and saw some of those comments here. That is a little over my head - at this point I kind of just want to run these passively and don't want to buy too much heatsink if it's unnecessary.
http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=BXRC35E2000D73BRIDGELUX4073511&IM=0
Can someone point me back on track please?