COB's and who makes them
- Thread starter spazatak
- Start date
canadian1969
Well-Known Member
Lots of panels with COBs, they have a higher failure rate than 3 watt diodes, marginally I hear. Aliexpress has quite a few to choose from. There are even COB DYI kits. personally I feel the stability and cost effectiveness of 3 watt diodes is the sweet spot for LED these days. eg http://www.bysenled.com/107.html (just an example, not a recommendation)
Chronikool
Well-Known Member
?
Do you have a link to these COB kits...?
I feel you can make most LED's stable with correct heat management, safety management and awesome management...
And cost effectiveness comes down to what you are willing to put in and get out of it...i believe...
If we say that 3 watt diodes are where itz at...progress is doomed...
SupraSPL
Well-Known Member
I will try and find the post, but I did the math in a thread here to show that generic COBs actually cost more/photon than Cree CXA3070s or Vero 29s. So yes, COB panels exist and they may seem cheaper at first glance, but they are not even cheaper when it comes to up front cost. Also, they run at a much lower efficiency so the electrical cost is higher. To put the final nail in it, if they are not cooled properly the generic COBs will suffer very significant lumen depreciation over time or even burn out completely. The Crees when properly cooled will not degrade over the years.
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canadian1969
Well-Known Member
@Chronikool
http://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=COB+DIY
Of course you probably could have googled it yourself, but vanqled.com is one off the top of my head that sells the parts for DIY COBs.
Cost effectiveness is not a belief system. 3 watt diodes are most prevalent because the demand is high, the cost has come down gradually over years and manufacturers order large quantities. Economy of scale. Its about getting the most bang for your buck, all I was saying. I did not at any time say 3 watt diodes were the "best" or whatever you inferred.
Improper heat management on any diode will shorten its life, if you are implying that COBs in general are not properly heat managed, that could account for the higher failure rate. Shenzhen Sanxinbao recently quoted me "up to 10% failure rate" versus 3 watt diodes with a "less than 1% failure rate", they pulled their COB panel shortly thereafter and have stopped actively marketing them; of course thats only one OEMs position so take it as you will. The subtext here is that the OEM went to the trouble of designing and adding a COB panel to their inventory then dumped it when they started failing. Could be a design flaw specific to them, but I have had zero issues with 3 watters so thats where I will stay for the time being.
http://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=COB+DIY
Of course you probably could have googled it yourself, but vanqled.com is one off the top of my head that sells the parts for DIY COBs.
Cost effectiveness is not a belief system. 3 watt diodes are most prevalent because the demand is high, the cost has come down gradually over years and manufacturers order large quantities. Economy of scale. Its about getting the most bang for your buck, all I was saying. I did not at any time say 3 watt diodes were the "best" or whatever you inferred.
Improper heat management on any diode will shorten its life, if you are implying that COBs in general are not properly heat managed, that could account for the higher failure rate. Shenzhen Sanxinbao recently quoted me "up to 10% failure rate" versus 3 watt diodes with a "less than 1% failure rate", they pulled their COB panel shortly thereafter and have stopped actively marketing them; of course thats only one OEMs position so take it as you will. The subtext here is that the OEM went to the trouble of designing and adding a COB panel to their inventory then dumped it when they started failing. Could be a design flaw specific to them, but I have had zero issues with 3 watters so thats where I will stay for the time being.
epicfail
Well-Known Member
Have you ever heard the saying "you get what you pay for"? Those chinese COBs look tempting by their cheap price but thats because they are inefficient, poorly made, dim versions of good COBS like Cree Cxa's and Bridgelux Vero's. Quality parts will last unless they are not properly cooled.
@spazatak - Soldering 2-4 cobs or 50-100 "3 watters" what would you rather do? COBs make it easier for the entry level diy hobbyist.
GroErr
Well-Known Member
Agreed, besides the fact that the Cree's are more efficient and will likely last longer than Chinese COB's. The COB's make it easy enough to put something together even if you haven't worked with anything like this before. I just ordered some 3070's and components to make my first 2 DIY panels, with solderless holders. The most difficult part for me will be seating them (flattening the surface, thermal paste, tapping a couple of screws per COB) as I've never done anything like that, the rest seems so simple I'm willing to dive into it. Thinking about connecting a bunch of 3w diodes seems like a nightmare and I wouldn't bother, whereas the COB's are doable for even me. It's a no brainer imo compared to working with 3w diodes.
Greengenes707
Well-Known Member
Remember when I took your last threads question the wrong way at first...this is the right thread/question for it....
Long story short...CXA and veros are not really cheaper in the end when you make them in a top performing situation. They are "cheaper"...not cheap, on a small DIY scale...but image putting an overhead cost on top of that, and start counting labor...and the ability to be cheaper than production of same quality and/or make a profit are basically gone...and then economies of scale start to mean a lot more.I think what you mean to ask is why aren't they making them with CXA's and VERO's?
There has been a shift to cob and/or multi chip panels. But nothing that is going to make the best smaller package chip panel makers scared.
The same reason you don't see a bunch of companies using xt-e's or nichia219...they cost more money ...a shit ton compared to un-named, unknown bins. And the major factories in china don't offer them as a part of the "custom" package...
No one has ever stopped any company in the past from actually using top notch chips if they wanted to...but instead of actually investing and making a great product, they go for a "alternative" or better yet "proprietary" chip that for some weird coincidence, is cheaper too
EDIT: I might have read/taken the question the wrong way.
I don't know what some of the better pre made panel builders are. AT plays dumb with me on tech stuff sometimes, so they are hard to judge for me. But he knows what I am planning so maybe they will see something of value(for them...we all have seen the value).
And I don't know what they other top few have up their testing sleeves. Good question
I could see hans having one COB in the center and building his spectrum around it with smaller 3w/5w. He's not very whit focused but one cob could maybe add something better than what he has going on white wise.
GroErr
Well-Known Member
Lol, not sure if that was a jab or joke, we get to pay more for everything here if that's any conciliation
Positivity
Well-Known Member
Interesting..haven't looked at alibaba in a while. They are marketing a lot of lights as DIY now..lol.
What does DIY have to do with their crappy lights? Because they need to be modified shortly after buying?..lol
Anything to make a buck...sheesh...
Out of that loop forever
What does DIY have to do with their crappy lights? Because they need to be modified shortly after buying?..lol
Anything to make a buck...sheesh...
Out of that loop forever
Observe & Report
Well-Known Member
Any 3070 can grow great buds. Z4 and AB bins put out 7.5% and 15% more lumens per Watt respectively but cost more and are harder to get. If you can get them they pay for themselves quickly. If you can't get them then growing buds now is worth a lot more than waiting weeks for better bins.
GroErr
Well-Known Member
yeah,
Thanks, I figured they would be alright. We don't have a lot of options in Canada, Digikey seems to be the one that stocks the most and beyond that I'd be paying a lot more with duties and shipping from the US. They'll definitely outperform my Chinese panels in flowering, I'm pretty sure of that
epicfail
Well-Known Member
yeah,
Thanks, I figured they would be alright. We don't have a lot of options in Canada, Digikey seems to be the one that stocks the most and beyond that I'd be paying a lot more with duties and shipping from the US. They'll definitely outperform my Chinese panels in flowering, I'm pretty sure of that
Not only is our selection worse and more expensive here but anything we import comes with a tax /fees and exchange rate. My rw-150's will be much cheaper than my diy's when done. I got a deal on 8 AB's from another member on this forum and so did a few others. Those Z2's will work great though, have you found a canadian distributor for extruded heaksinks? The 5.886" from HSUSA cost as much to import/ship as it does to buy. Don't even get me started on the price of drivers in this country.
USA vs. Canada
GroErr
Well-Known Member
Not heat sinks, there has to be some but haven't found one. Even with shipping though HSUSA is probably cheaper than buying them here. Bought the Meanwell drivers on e-bay, cheaper than anywhere and w/free shipping. Not really a save money project, but better quality/efficiency than most marketed panels, and you build what you want/need. You can buy custom like those BML's but then you're into bigger dollars again.