Need 4x cxb3070 CB or cxb3590 DD bin!

SupraSPL

SupraSPL

Well-Known Member
littlejacob said:
Bonjour
How low you have to drive your cxa in vegg to be able to put the lights at 6/8 inches from the plant?
And how deep goes the light at this power? ThanksCU!
Click to expand...
I have them on a dimmer from 200mA to 380mA. At 200 (~13W ea) and can handle about 1.5 foot depth of canopy (vegging). At 350mA (24W) it is no problem to handle a 2.5' canopy depth (vegging). That said, if you increase the intensity they will veg up faster.
 
SupraSPL

SupraSPL

Well-Known Member
led-it-be said:
@Supra: Can I ask why you prefer 5000K over 6500K? The chlorophyll a activity is highest in blue light, so in theory 6500K should be more effective, no?
Click to expand...
Blue light is good for photosynthesis but each photon carries a lot of energy relative to the other colors and therefore requires more energy to create. So in practice we want to use as little blue as is necessary to balance photomorphogenesis (light mediated development). KNNA recommended 25% blue for vegging and 15-20% blue for flowering (by power). Based on those guidelines, CXA 5000K should be ideal for vegging because it is about 24% blue by power.

Here is an example of how 6500K compares to 5000K, the blue peaks are matched in this case which kind of confuses the issue but you can see how much higher the proportion of blue is in 6500K
Citizen CLU SPD.png
 
littlejacob

littlejacob

Well-Known Member
SupraSPL said:
I have them on a dimmer from 200mA to 380mA. At 200 (~13W ea) and can handle about 1.5 foot depth of canopy (vegging). At 350mA (24W) it is no problem to handle a 2.5' canopy depth (vegging). That said, if you increase the intensity they will veg up faster.
Click to expand...
Bonjour
@350mA what is the distance between cob and plant?
We talk about cxa 3590 5000ºk db???
CU
 
led-it-be

led-it-be

Member
I jumped over my shadow and bought 1 cxb3070 6500K BD and 4 cxb3070 5000K BD from jerry.

I'll try to grow lettuce at very low power first, to see what the lowest possible wattage is for plants to still grow under cobs.
Does anyone know the luminous efficacy of the mentioned cob at 4W ?

The table here shows efficacy at a minimum of 11W (206lm/W :shock:): http://pct.cree.com/dt/index.html
 
EfficientWatt

EfficientWatt

Well-Known Member
Hi,
You sure about the cxb3070 5000K BD ? Didn't see them is his stock ..

For PCT, don't forget to change Tj to something like 50°c if you want to have a more real life estimate.
It drops to 199.3@45°c .. !

led-it-be said:
I jumped over my shadow and bought 1 cxb3070 6500K BD and 4 cxb3070 5000K BD from jerry.

I'll try to grow lettuce at very low power first, to see what the lowest possible wattage is for plants to still grow under cobs.
Does anyone know the luminous efficacy of the mentioned cob at 4W ?

The table here shows efficacy at a minimum of 11W (206lm/W :shock:): http://pct.cree.com/dt/index.html
Click to expand...
 
Last edited:
led-it-be

led-it-be

Member
EfficientWatt said:
Hi,
You sure about the cxb3070 5000K BD ? Didn't see them is his stock ..

For PCT, don't forget to change Tj to something like 50°c if you want to have a more real life estimate.
It drops to 199.3@45°c .. !
Click to expand...
Jerry confirmed, and it says so on my invoice:

CXB3070 6500K BD$36.50 1
CXB3070 5000K BD$36.50 4

You are right about the temp, although I wonder if Tj could be lower than 45°C at only 4-5W per cob (my goal is to go that low and see if the plants survive).
 
littlejacob

littlejacob

Well-Known Member
Bonjour
Is there another place than kb where it is possible to get the same bin?
Cause since Jerry stop china post option we must add 40 $ to the bill...
So for a single 200w pannel...4 cobs... we must add 10 $ to each (+paypal tax!) We must buy more...
I believe you done research so do you know where to look?
Have a great day ★
 
U

usernamereview

Well-Known Member
led-it-be said:
You can look up bins in the datasheet, here: cxb3590.

There are some bins not listed on there, but you can find them on a great comparison tool from Cree here.
They even list lm/w numbers at different currents.
Click to expand...

Thank you for re-providing this info/chart. Sometimes its hard to find simple direct answers to question on this board b/c there are so many convo's an long threads.

Was looking to order LEDs and wasn't quite sure the ranking or grading of LED's from highest to lowest.
 
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