50w/100w Cheap China COB 30mil 35mil 45mil

TRIBUNAL

TRIBUNAL

Well-Known Member
I ordered the CXA3070 Z4.
I don't have the cash for another atm.
I would like to order an additional chip to replace the rest of the CFL's until I have the cash for the top shelf again.
The info on the cheap china COB's is pretty limited on details.
There seems to be 3 sizes: 30mil, 35mil, and 45mil.

>I suppose bigger means a better spectrum and more surface area for heat transfer so = cooler, better chip..?

>I am thinking the 50w or 100w running at half power will increase efficiency in a similar way that Supra has pointed out happens with the Cree CXA's...?
I ignored the noname chips and The three names I have found are: Epistar, Bridgelux, and ... I feel like Dumb Rick Perry, I forgot the third thing... anyway...
I found 50w Bridgelux for $10 ( http://www.ebay.com/itm/1-PC-50w-Warm-White-3000-3500k-Led-COB-Chip-Bridgelux-45-mil-led-light-DIY-/201072278015?pt=LH_DefaultDomain_0&hash=item2ed0d779ff ) which I would run at about 90% for a little while. Seems like the best bet for a cheap temp COB.
Or Maybe I should just get the cheap ass 30-35mill 100w no name china junk and run it at half?
Thoughts?
Any better recommendations?
TY :)
 
C

churchhaze

Well-Known Member
Epistar for some reason is allowed to sell their products as "bridgelux", when they clearly aren't.

The good news is they don't try to make their products also look the same. A Bridgelux vero 18, doesn't have any ripoff lookalike eggs I know off (yet).
 
Abiqua

Abiqua

Well-Known Member
churchhaze said:
Epistar for some reason is allowed to sell their products as "bridgelux", when they clearly aren't.

The good news is they don't try to make their products also look the same. A Bridgelux vero 18, doesn't have any ripoff lookalike eggs I know off (yet).
Click to expand...
the dies are bridgelux or licensed or fake, but these dies are also from tech that is over a decade old it seems....so even if they are Bridgelux [meaning nothing, since they are actually a die manufacturer and make for other companies, like a Foxconn for Ipads] the substrate was still added after by someone other than BL and with no docs, it s a guess unless we start making powder for the GC machine....:)
 
SupraSPL

SupraSPL

Well-Known Member
I ordered a pair of the generic warm white 50W from Ali. Here is the first one:
DSC07943a.jpg

The second was not much better. Neither were flat, the aluminum they are mounted on is warped, pinched at the edges like every aluminum board I have ever checked. You are correct though, running these COBs soft can significantly increase the efficiency and they are cheap enough that we can afford to run them soft (5W instead of 50W)

This $10, 100W warm white "Lohas" arrived undamaged. But the silicon was very unevenly spread across the COB surface, most of it is on one side. But every tiny LED inside is lit uniformly. It also has the warped aluminum board so I sanded it flat, mounted it on a decent cpu cooler, cranked 3.2A through it and it held up fine. Temp droop was good, only 1.5% but I cannot recall the current I was running for that test. As expected, the output on the luxmeter was poor at 2.45A (and every other current) compared to the CXA3070 AB and Vero 29. So the efficiency is not nearly as good as the $30-$40 COBs, but if we run it softer it may have some good uses.

We might be able to get generic 100W chips for as little as $6 so it would interesting to compare a $4.37 Vero10 versus 100W generic both running at 150mA (Vero10 3.7W and 100W generic at ~4.8W). I have some $6 100 watters on the way for testing, but here are the results of what I have on hand:

$4.37 Vero10 2700K @ 157mA -> 385 lux/W
$10 Generic 3000K "100W" @ 157mA -> 409 lux/W
$2.80 Generic 3000K "50W" @ 157mA -> 158.8 lux/W (dang i want my heatsink back)
$42 CXA3070 3K AB @ 157mA -> 526lux/W (for reference)

In summary, if you think of the 100W COB as a 20W COB, and run it at 5W, it is not half bad. But the Vero10 does not need to be sanded and it has a lot more red/deep red output.
 
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alesh

alesh

Well-Known Member
Abiqua said:
the dies are bridgelux or licensed or fake, but these dies are also from tech that is over a decade old it seems....so even if they are Bridgelux [meaning nothing, since they are actually a die manufacturer and make for other companies, like a Foxconn for Ipads] the substrate was still added after by someone other than BL and with no docs, it s a guess unless we start making powder for the GC machine....:)
Click to expand...
Bridgelux chips are not very good if you look at their specs. That and poor packaging/quality/thermal design...
Vero series actually utilizes chips from Toshiba, only packaging is from BL.
 
TRIBUNAL

TRIBUNAL

Well-Known Member
I really tried to answer this myself before posting but god dammit this is difficult information to obtain.
So if i want to use the Vero 18 at about 2.0a or slightly less if need be, what driver options do I have?
Open frame is fine if it's cheaper.

Someone should help those manufacturer's design a search engine, that works.
 
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