When are the commercial cob panels coming

A lot of people already have oscillating fans setup in a way that might blow over their "semi-passive" sinks, but I think in general Rahz is right. Different people have different design requirements. It's not a complete waste to have fans agitating the air. There's gotta be some balance as no matter how low the price of cobs gets, the price of aluminum will likely only go up.

However, when you pick more efficient cobs, and drive at lower currents, the amount of total heat generated is smaller, and thus the requirement for the expensive aluminum sinks go down. As the price of cobs goes down, it might make sense to buy more cobs and underdrive to what is now considered extreme levels just for the sake of lowering expensive heat sink requirements.

Fantastic

Abiqua said:

http://opticgrowlights.com/

Cree Cxb and Vero....the only thing better would be to build it yourself...

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churchhaze said:

The cheap no-name asian grow lights all have cases. It's only DIY builds that don't. A lot of the advantages you listed are not actually advantages.

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NO ?
Almost none thermal derating of drivers and their caps ain't a great advantage ?

churchhaze said:

While "open frame drivers" is a cost/space advantage, "1 driver per cob" is not. I hang my 1 encased driver on the ceiling of my tent using straps. "1 driver per cob" is one of the major criticisms by LED critics, and I agree with that criticism. That's insane. In fact, the 1 driver also has high efficiency. (upto 94%), which was a major reason why I picked it. It even looks sleek! I love the way HLG-C looks.

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Price/cost effectiveness was never mentioned by me ,neither as advantage ,neither as disadvantage .

churchhaze said:

Look, I think the quality of your work is amazing (way better than I could do with metal), but to suggest your lamp has better functionality because of it's sleek form is a bit of a stretch. Is the goal really to make the lamp more silent?

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Yes,amongst others,yes.The fixture has to be silent.

churchhaze said:

Wouldn't removing the case make it even more silent? (less back pressure and turbulence)
.

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Think it over for a minute or so ...
Back pressure ? Turbulence ? Why ?
I mean ,how those things will ever happen ,if the design won't allow ?

churchhaze said:

Also, without a case, there's extra money in the budget for a larger heat sink. You put 4 vero 29 at 2.1A right next to each other on a relatively small heat sink so it makes sense you'd complain about fan noise. You can not hear anything from my vero 18 based UFO killers at 700mA. (4 less powerful heat sources on a larger heat sink, farther away from each other) This might be moot point if a case is required for certification, but that's not your argument.

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-Correction : 4 x 1,53 A
-Fan noise : Less than 19dB ( most dB meters won't even register the fan's noise even at 10 cm distance ... )
- Max Tj of the four Veros is Ta+25C at 1530 mA .... Beat that ,I challenge you ..
Just do not use a case ....
See if you can make it even close to Ta+25C and then ,we can continue , this discussion further on ..

As i've already mentioned ...
Diversity ..
Nothing and none is perfect ...
Some though ,are pretty much close ....

Trust me , to built the lights I built ,it takes lot more ,
than just placing a COB on heatsink and then connect a driver ....
There's plenty of calculations ,simulation ,real testing and more ,
that one can not see being connected or attached to the fixture ...

Trust me ,simplicity to be achieved ,needs a lot of complexity .
As for high efficiency to be achieved ,needs more than just high quality ,low driven COBs and/or drivers .
Another thing making a "efficient " device ,another thing the "efficient approach " of making a device .

Cheers.

I'm more concerned about lint, humidity, and sulfides, than I am with higher temperatures causing the driver to degrade faster. An encased driver will not have issues with lint or sulfides in the air. So far I have not heard of any HLG-C drivers crapping out. It would be nice to have easier access to the capacitors, but I don't see it as a huge issue because it's unlikely one of them will go bad in the near future.

I'm not sure how you think a larger heat sink with less total heat sources on it would have a harder time keeping Tj lower than an encased lamp with a smaller heat sink and larger heat sources. I also used heat sink simulations to design my panels, although I think that's somewhat irrelevant. I actually disagree with the necessity of optimizing cob placement for perfect temperature distribution, and would favor sacrificing by having slightly more poor temperature distribution in order to get slightly better lighting distribution. I do not think putting 4 vero 29 so close together makes a device more of an effective approach in the slightest bit.

AquariusPanta said:

Just one thing that I haven't had the chance to discuss before, which is the trade off between cheaper power bills or better COB efficiency. It's been documented by our fellow grower and teacher, @SupraSPL, that fans make a remarkable difference in how heat sinks are cooled and ultimately how cooler junction temperatures can drop by just adding a wee bit of breeze. I suppose one could have a large enough heat sink but some people are going to want compact and effective fixtures, ya know? The market's lighting business is growing, and in favor of LED.

Also, most fans that I've tinkered with run anywhere between 100ma~200ma - not a huge ball breaker.

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I agree fans don't add a lot of wattage requirements. However, before getting too caught up in the benefit of fans it's worth considering that the reason a fanned sink provides more light is primarily because the voltage goes up. It's not so much the power bill but the initial cost per watt for the unit that's mitigated with fans.

churchhaze said:

I'm more concerned about lint, humidity, and sulfides, than I am with higher temperatures causing the driver to degrade faster. An encased driver will not have issues with lint or sulfides in the air. So far I have not heard of any HLG-C drivers crapping out. It would be nice to have easier access to the capacitors, but I don't see it as a huge issue because it's unlikely one of them will go bad in the near future.

I'm not sure how you think a larger heat sink with less total heat sources on it would have a harder time keeping Tj lower than an encased lamp with a smaller heat sink and larger heat sources. I also used heat sink simulations to design my panels, although I think that's somewhat irrelevant. I actually disagree with the necessity of optimizing cob placement for perfect temperature distribution, and would favor sacrificing by having slightly more poor temperature distribution in order to get slightly better lighting distribution. I do not think putting 4 vero 29 so close together makes a device more of an effective approach in the slightest bit.

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I stand on a different ground ...

I'm definately more concerned about high temperatures ,than lint,humidity and sulfides.
Afterall ,all the bare electronics in the fixtures I build are protected by a thin layer of special insulating-protecting varnish -mainly used in aviation electronics .
http://www.aeroakku.com/product_info.php/language/en/info/p239_TESLANOL-T7-UNI-PLAST.html/XTCsid/36

Excuse me ,but for me size and total surface of a heat sink ,
are not the only variables that determine the efficiency of the heat sink ..
At least regarding the active cooling of a heat sink ...
There are others like fin spacing ,base thickness ,fin number ,heat sink material ,
fan size and air velocity ,that make lot's more difference than size or area of heat sink
on an active cooling design ...

And yes ,actually " putting 4 vero 29 so close together" makes a very effective device ,
to a level you can't even imagine *...
At least for it's given overall size and the space it is supposed to cover ...

(*At one point I hope I can show you with some pics or a vid ,
showing how "effective" those devices I build ,actually are ...
I think you will be amazed , at the least .... I was and still am .... )


As for LED drivers ...
Who ever told you that are without any "weak points " ?
Or do you actually think that they will last ,same as the COBs will ?
You 've some homework heading your way ...
Just for starters :

http://www.luxdrive.com/library-documents/led-drivers-and-capacitor-reliability/

http://www.lrc.rpi.edu/programs/solidstate/cr_driverlife.asp

http://www.mondoarc.com/technology/LED/228719/driving_responsibly.html


Once more ...
Most people think that making a LED grow light is relatively simple and easy ...
Well...They 've every right to think so ...Not that it is actually a true fact ...

Cheers.

Make no mistake, I probably would be amazed by your results. I would love to see it one day if you feel more comfortable showing. Your lamps are definitely of the highest construction quality. I can't argue with that. My construction quality is crap in comparison. Metal work is very new to me. I also need to learn to make PCB's using the toner method like you. It always comes out so nice when you do it.

However.... a lot of the people we've been guiding to make DIY builds have been making pretty awesome naked builds with HLG-C and well sized heat sinks, fans, and spacing. You say that making a lamp is not simple, but we're trying to make it simple. Having one driver per cob means tons of wires everywhere. I've never used an encased HPS lamp, just batwing reflector attached to a mogul base, and a remote ballast. I've also never had an HPS lamp run at 40V max. Using larger drivers with higher voltages significantly reduces wiring to the point where a case seems unnecessary. I have 1 driver powering an entire 2'x4' tent with 1 series circuit. It's almost as if it was a 193W HPS lamp.

What's nice is the HLG-C drivers (as well as other drivers) have screw holes for mounting, which I mount to the frame of my wood boxes, or use straps to mount to the top of tents.

I'm guilty of using the words easy a lot. But, compared to other things I've taken on, I think it is. I see people do amazing things with their hands pretty often whether it's building a car, or a boat, renovating homes. It just takes a desire, a passion, to do it.

In case you haven't noticed I'm quite passionate about mj. It's a long standing affair... So making a good light comes completely naturally. At least I think it's good enough, especially compared to some of the lights I've bought.

Just got another result from a friend.. Burned out "high end" fixture. Happens so often, and I don't even know that many indoor growers.

Edit.. I'd like to add just one thing. A lot of fixtures I see built I don't quite agree with everything for whatever reason. But the funny thing is, they'll probably still outlast something they would have bought commercial. Excluding the few top lights with high standards... Even than maybe as long a life. I personally haven't seen many failures that I can recall

churchhaze said:

Make no mistake, I probably would be amazed by your results. I would love to see it one day if you feel more comfortable showing. Your lamps are definitely of the highest construction quality. I can't argue with that. My construction quality is crap in comparison. Metal work is very new to me. I also need to learn to make PCB's using the toner method like you. It always comes out so nice when you do it.

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Make no mistake ,currently I do not have neither the time ,neither the "freedom" to grow..
(Hope that this will change soon enough ...)
It's not me being uncomfortable to show ,it's the actual users of the devices that are not comfortable showing
their plants ...Still ,I was invited in some cases by them ,to take a look at their grow-ops ,featuring my builds..
Well ,to put it shortly ,in most cases ,the results up till now ,exceeded by far ,my own expectations ..
(And came to realise that I'm not that good grower ,as I previously thought ...FGS a "newbie " got results ,
that I never had myself ,during 10 years of growing !!! Beginners luck ? )

PCB making with laser toner is very -very easy ...
It just needs a bit of practice ..
Although ,I liked the perforated board job of yours !
Quite neat !

Cheers.

stardustsailor said:

PCB making with laser toner is very -very easy ...
It just needs a bit of practice ..
Although ,I liked the perforated board job of yours !
Quite neat !

Cheers.

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Ah Yes... The stripboard... Ugly as hell, but it's been working pretty well so far... lol

churchhaze said:

Ah Yes... The stripboard... Ugly as hell, but it's been working pretty well so far... lol

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I like using them and I like the looks.
BTW This is the most useful pattern I've found so far.

For some reason, most driver failures I have come across so far have been non-potted generic drivers. So I assumed that the potted drivers spread the heat away from the hottest components better than open air design (unless active cooled). The downside being that potted components are heavier and not user serviceable. Although I dont expect Mean Wells to ever need to service.

I just swapped one tent over to HLGs and I have full confidence that will will run for many years. Swapping the other tent over to Mean Well gradually. Even at full power they are cooler to the touch than the 800mA 90% generic drivers I was using. BUT the potted generic drivers worked perfectly for many cycles without a single failure as well.

Running at 210W and passive cooled, surface temp of the drivers 35-36C, (ambient currently 18C)


Managing Heat Transfer with Potting and Encapsulating componds

As far as prettiness of the fixture, there is nothing wrong with that I love it. BUT for me function comes before form. When editing a film they use storyboards and work copies before polishing the final cut. I think we are in the same situation so I want to find out what works best before investing too much in aesthetics.

SupraSPL said:

For some reason, most driver failures I have come across so far have been non-potted generic drivers. So I assumed that the potted drivers spread the heat away from the hottest components better than open air design that lacks active cooling. The downside being that they are heavier and not user serviceable.

I just swapped one tent over to HLGs and I have full confidence that will will run for many years. Swapping the other tent over to Mean Well gradually. Even at full power they are cooler to the touch than the 800mA 90% generic drivers I was using. BUT the potted generic drivers worked perfectly for many cycles without a single failure as well.
View attachment 3410638 View attachment 3410637

Managing Heat Transfer with Potting and Encapsulating componds

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Sorry for my ignorance but what is a 'potted driver'?

When the electronics are entombed in this stuff:


SDS uses the HLP drivers and which are open frame and not potted. The HLN series are the same drivers, except potted and in a case. The HLGs are also potted. So we are discussing, which approach will have better reliability long term?

BTW thank you SDS for bring the HLP and HLN drivers to our attention, great options for certain COB applications.

SupraSPL said:

When the electronics are entombed in this stuff:

SDS uses the HLP drivers and which are open frame and not potted. The HLN series are the same drivers, except potted and in a case. The HLGs are also potted. So we are discussing, which approach will have better reliability long term?

BTW thank you SDS for bring the HLP and HLN drivers to our attention, great options for certain COB applications.

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Thanks. So potted means enclosed and filled with some sort of thermal compound?
edit: Ok, I should have googled more.

Rahz said:

I agree fans don't add a lot of wattage requirements. However, before getting too caught up in the benefit of fans it's worth considering that the reason a fanned sink provides more light is primarily because the voltage goes up. It's not so much the power bill but the initial cost per watt for the unit that's mitigated with fans.

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Yes, the fans we typically use over our heat sinks don't take up a bunch of watts. I try not to think about costs too much, but instead more of what I can get away with in terms of COB efficiency potential. In other words, Rahz, if I can achieve ~45% efficiency with a Vero 18 driven at 700mA when junction temperature is ~30*C (with the aide of a fan), then it's worth the extra costs in power consumption and start up cost.

We may be on two different pages here, Razzy, but hopefully you can understand what I see as most important when it comes to building a fixture.

stardustsailor said:

simplicity to be achieved ,needs a lot of complexity .


Cheers.

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This may be my favorite line of yours...

For me the question is, how much more is a person willing to pay for a passively cooled lamp with superior efficiency? 20% more? Or is a fanned lamp running close to industry standards a better deal at 20% less?

Rahz said:

For me the question is, how much more is a person willing to pay for a passively cooled lamp with superior efficiency? 20% more? Or is a fanned lamp running close to industry standards a better deal at 20% less?

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Start a poll!