DiY LED - Cree CXA3070

[alesh]

I'm placing a order for my driver and cob. I found a top bin cxa3070 3000k (ab) for 64$... that's 14$ more than the mid level bin (z4). Is it worth it? What is the difference between the low, mid and top bins? Z2 Z4 AB? Also I'm planning to use a meanwell lpc60 1040. Is that better than a chinese 1500? I know meanwells 1500 isn't power corrected and is less efficient. I don't know exactly what that means yet lol but I know it's no Bueno! Just not sure if a 1040 is too weak. The way I understand it is the higher the milliamps the brighter but also hotter which means they burnout faster and aren't as efficient. How am I doing so far?

PS I'm using an artic 11 pc cooler for this single cob light

Prices are dropping and $64 for CXA3070 AB is way too much. Go with more efficient and cheaper CXB3070 [URL='http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&keywords=cxb3070']AB[/url] for $40. Or even cheaper from Kingbrite - more info there.

 

[Cali weed]

What is the difference between the cxa and cxb? What is the difference in low vs top bin? What is power factor corrected? is it better run the generic 1.5 amp driver or the meanwell 1040? Sorry to bug but I'm new to this and Wanna get the ball rolling soon. Thx for all the help

 

[Doer]

What is the difference between the cxa and cxb? What is the difference in low vs top bin? What is power factor corrected? is it better run the generic 1.5 amp driver or the meanwell 1040? Sorry to bug but I'm new to this and Wanna get the ball rolling soon. Thx for all the help

!- same thing but quite a bit more efficient and costly but you can't get them yet, CORRECTION: Can't get the CXB3590s yet. Bs are more efficient.

2- All XLamp LEDs are tested and sorted by color and
brightness into a unique bin. Each bin contains LEDs
from only one color and brightness group and is uniquely
identified by a bin code. White XLamp LEDs are sorted by
chromaticity (color) and luminous flux (brightness). High
Voltage White XLamp LEDs are sorted by chromaticity,
luminous flux and voltage. LEDs are shipped on reels
containing LEDs from one bin and are always labeled
with the appropriate bin code.
[PDF]Binning & Labeling - Cree, Inc.

3-figure the power factor of a load by dividing the true power by the apparent power:

(figuring out true power is important in LED. PFC is when capacitors and other electronics are used to improve the circuit's power consumption) For example corrected power factor of (1.5kW / 1.5009 kVA), or 0.99994, and a new total current of (1.50009 kVA / 240 Volts), or 6.25 amps, a substantial improvement over the uncorrected value of 9.615 amps! This lower total current will translate to less heat losses in the circuit wiring, meaning greater system efficiency (less power wasted).
http://www.allaboutcircuits.com/vol_2/chpt_11/4.html

4- the lower the amps to the LED the more efficient they are. And they think that may be because driving higher currents drives off extra electrons as heat.

 

[Cali weed]

Thx doer, that's exactly what I needed. Alesh advised me to go with the cxb. I know you said there not available yet but Alesh gave me this link and it seems legit. So obviously this is the better choice right? Also 24$ cheaper than the cxa top bin at mouser.

 

[Doer]

Thx doer, that's exactly what I needed. Alesh advised me to go with the cxb. I know you said there not available yet but Alesh gave me this link and it seems legit. So obviously this is the better choice right? Also 24$ cheaper than the cxa top bin at mouser.

Woops, I was thinking the 3590s so, that's good man!

 

[Cali weed]

Okay cool. I think I'll go with that unless this company on alibaba gives me the cxa for cheaper. Thx for the help bud

 

[apoulin]

Thx doer, that's exactly what I needed. Alesh advised me to go with the cxb. I know you said there not available yet but Alesh gave me this link and it seems legit. So obviously this is the better choice right? Also 24$ cheaper than the cxa top bin at mouser.

You won't be disappointed with the cxb3070. Bought 4 myself

Something to keep in mind with the more efficient cxb, more efficiency = more tasty nugs

 

[Cali weed]

Sooooo lol..... New question what is the cxb's top bin? Kingbrite has the cxa3070 ab for 28.50
They also have the cxb 3070 ad for 37.50. Is the ad the top bin?

 

[alesh]

Sooooo lol..... New question what is the cxb's top bin? Kingbrite has the cxa3070 ab for 28.50
They also have the cxb 3070 ad for 37.50. Is the ad the top bin?

Yep, AD is top bin for CXB3070. It's about 6% more efficient than CXB3070 AB and even more than CXA3070 AB. If I'm not mistaken Kingbrite also has CXB3590's but @Doer seems to not like them and keeps saying that you can't get them.

 

[wirat]

Supra, I saw one of your build posts on another forum where you mounted the COBs to Arctic 11s. I have two quick questions for my own clarification;

1. If you don't want to (or cant) drill or use an OEM holder, can you use Kapton tape as the only source to secure the COB to the heatsink?

2. If one wanted to use an Arctic Alpine 11 heatsink for the COB, is the Arctic Alpine 11 pre-applied OEM CPU heatsink paste suitable for LED COBs? The idea being that the DIY'er could simply buy the COBs and Arctic 11s, then attach the COBs directly to the Arctic 11s out of the box using Kapton tape as described in #1...

Thanks!

 

[Doer]

Yep, AD is top bin for CXB3070. It's about 6% more efficient than CXB3070 AB and even more than CXA3070 AB. If I'm not mistaken Kingbrite also has CXB3590's but @Doer seems to not like them and keeps saying that you can't get them.

No, I don't say that. They are not completely UN-obtainum this week. And when did I ever say I "didn't like" a Company in China named Kingbrite? Not me. I was the one that buys Lab Glass from China. No problems at all yet, with these Companies for me.

Kingbrite doesn't list them yet, on their site. I think you, or someone, was in Comms with them and they said the could get a couple pieces in a few bins, only.

Yet, last week DigiKey had none and now they are order able. Same price as the CXA. $68

Product Lead Time Estimates
Digi-Key Part NumberCXB3590-0000-000R0HCB30G-ND
Manufacturer Part NumberCXB3590-0000-000R0HCB30G
DescriptionLED ARR 30MM 3000K 80CRI 11K LM

QuantityShip Date Estimate
(mm/dd/yyyy)
84/1/2015
Ship dates are approximate and subject to change.

 

[Doer]

We all wait for China un-less we are in big hurry. The prices there make this all make sense.

So. I am waiting to order from Kingbrite. I love Kingbrite, especially the name

 

[beppe75]

Hello to all you guys, its my first post here on RIU and i wanted to thank you all for sharing your knowledge.
i did my fair share of reading and i feel ready to try and build my first led diy grow light but i need some help... initially i had the idea to build a 5 cob panel of cxa3070 run at 2a but i understood the light would not be very efficient so after checking my options i think i'm going for 5 x CXB3070-0000-000N0HAB30G-ND which are the best availeble (if i got it right) at the price of almost 42 euro each at digikey.it ( = 210e).
i plan to run them on 1x HLG-185H-C1050B which is priced at 66e at mouser.it and these are the best options i found. i plan to cool them with 5 arctic 64 gt rev 2 which i found at 4.92ehttp://www.amazon.it/ARCTIC-Alpine-Rev-Dissipatore-raffreddamento/dp/B001A5V1K2/ref=sr_1_1?ie=UTF8&qid=1426948382&sr=8-1&keywords=arctic+gt64+rev+2
wanted to use these switches : http://www.amazon.it/dp/B00EJ64MR8/ref=wl_it_dp_o_pd_nS_ttl?_encoding=UTF8&colid=1VAMHG6WXZDWD&coliid=ICII2EMKPCZVP do you think the are ok?????
would you help me with some advice or anything you think i can do better? it would be enormously appreciated.
what do you think about efficiency of this build? any numbers i have still to understan the math behind it?
also i plan to use the lamp on a 3'x3' grow tent so i belive i'm a little down at 21.1 w/ftsq but i plan on adding two more at a second time..... Thank you all....
@SupraSPL your knowledge is welcome man...

 

[Dloomis514]

Hello to all you guys, its my first post here on RIU and i wanted to thank you all for sharing your knowledge.
i did my fair share of reading and i feel ready to try and build my first led diy grow light but i need some help... initially i had the idea to build a 5 cob panel of cxa3070 run at 2a but i understood the light would not be very efficient so after checking my options i think i'm going for 5 x CXB3070-0000-000N0HAB30G-ND which are the best availeble (if i got it right) at the price of almost 42 euro each at digikey.it ( = 210e).
i plan to run them on 1x HLG-185H-C1050B which is priced at 66e at mouser.it and these are the best options i found. i plan to cool them with 5 arctic 64 gt rev 2 which i found at 4.92ehttp://www.amazon.it/ARCTIC-Alpine-Rev-Dissipatore-raffreddamento/dp/B001A5V1K2/ref=sr_1_1?ie=UTF8&qid=1426948382&sr=8-1&keywords=arctic+gt64+rev+2
wanted to use these switches : http://www.amazon.it/dp/B00EJ64MR8/ref=wl_it_dp_o_pd_nS_ttl?_encoding=UTF8&colid=1VAMHG6WXZDWD&coliid=ICII2EMKPCZVP do you think the are ok?????
would you help me with some advice or anything you think i can do better? it would be enormously appreciated.
what do you think about efficiency of this build? any numbers i have still to understan the math behind it?
also i plan to use the lamp on a 3'x3' grow tent so i belive i'm a little down at 21.1 w/ftsq but i plan on adding two more at a second time..... Thank you all....

What will you be using to spread them out? Or will they hang from the ceiling individually?

 

[Jeeyah]

Damn. I've been getting Z2's on Digikey. What was I thinking?

 

[Doer]

Supra, I saw one of your build posts on another forum where you mounted the COBs to Arctic 11s. I have two quick questions for my own clarification;

1. If you don't want to (or cant) drill or use an OEM holder, can you use Kapton tape as the only source to secure the COB to the heatsink?

2. If one wanted to use an Arctic Alpine 11 heatsink for the COB, is the Arctic Alpine 11 pre-applied OEM CPU heatsink paste suitable for LED COBs? The idea being that the DIY'er could simply buy the COBs and Arctic 11s, then attach the COBs directly to the Arctic 11s out of the box using Kapton tape as described in #1...

Thanks!

While we wait for his answers, here is everything about Kapton Tape. I have been thinking about it, too.

You get some elongation as the temp. rises but not much.

http://www.dupont.com/content/dam/assets/products-and-services/membranes-films/assets/DEC-Kapton-summary-of-properties.pdf

Some of the properties such as tensile strength will degrade to zero over time, in heat. It doesn't like UV exposure, or water.

But, I am not sure what you mean. Just use it like masking tape? Or is it double sided between the COB and the sink? The problem is not attachment, you know?

The problem is to create a thermally efficient bond between the junction and the heat sink. Not an easy problem. To see the problem you need imagination as it happens on the microscopic level.

Supra when through enormous work to polish his heat sink. Why? He made the surface as gap free smooth as possible. It shines, it reflects, it looks like 4 wires when there are only 2.

I saw a prototype of our latest processor yesterday. It is polished as fine as a mirror in a telescope. Why? Same thing. It is what the polished side the heat sink clamps to.

So, heat can only transfer directly molecule to molecule. If a molecule of aluminum is in DIRECT contact with molecule of COB bottom surface, heat will flow easiest. But, if there is the most sub-microscopic gap in smoothness there, it is an AIR GAP. <GASP> Now the heat has to go through molecules of air first.

This is why use expensive silver based gap filling compounds, because the gaps we are talking about are not visible to the eye.

So, can Kapton apply enough pressure to keep the gap filler happy? That's the main question.

That's why we use screws, polish work, and gap filler.

 

[Doer]

There is gap tape, also. It is a thin membrane with double sided adhesive. There are kinds that will melt at the first temp cycle only. After cooling it won't melt again.

So, good gap filler and attachment.

 

[Jeeyah]

Supra, I saw one of your build posts on another forum where you mounted the COBs to Arctic 11s. I have two quick questions for my own clarification;

1. If you don't want to (or cant) drill or use an OEM holder, can you use Kapton tape as the only source to secure the COB to the heatsink?

2. If one wanted to use an Arctic Alpine 11 heatsink for the COB, is the Arctic Alpine 11 pre-applied OEM CPU heatsink paste suitable for LED COBs? The idea being that the DIY'er could simply buy the COBs and Arctic 11s, then attach the COBs directly to the Arctic 11s out of the box using Kapton tape as described in #1...

Thanks!

You can use the tape. I've done it. The Arctic 11 comes with pre-applied paste. However, I just sort of fried one of them. I don't think it had a very good thermal connection, if at all. The yellow circle cracked and peeled like paint. About, 50% of the chip lights up now. I have a new one coming in the mail. Just be careful, and make sure there's no gap in between the chip, and sink.

 

[Doer]

http://www.chomerics.com/products/thermal/gap-fillers/index.html
gap filler pads
THERM-A-GAP™ gap fillers are a family of low modulus (soft), thermally conductive silicone and non-silicone elastomers for applications where heat must be conducted over a large and variant gap between a semiconductor component and a heat dissipating surface.

• Soft binder provides low modulus for conformability at low pressures
• Low modulus allows materials to make up for large tolerance stack ups
• Low pressure applications

Gap fillers are used to bridge large gaps between hot components and a cold surface. The gaps are not only large, but their tolerances can be ±20 % or greater. This means that the gap filler must have sufficient compliance to fill such spaces without stressing components beyond their safe limits. Non-silicone gap fillers are available for silicone sensitive applications.

Gap fillers are supplied in pad-form over a wide range of thickness, 0.25 to 5mm, and can be molded into complex shapes. THERM-A-GAP GELs are also supplied as pre-cured, single component compounds that can be dispensed over the heat generating component.

 

[Doer]

You can use the tape. I've done it. The Arctic 11 comes with pre-applied paste. However, I just sort of fried one of them. I don't think it had a very good thermal connection, if at all. The yellow circle cracked and peeled like paint. About, 50% of the chip lights up now. I have a new one coming in the mail. Just be careful, and make sure there's no gap in between the chip, and sink.

A heat destroyed COB. Do you have a picture?