cheap ebay DIY LED

[naoki]

larry, CXB3590 (top shelf) is 5000K because it was cheaper. The bottom is 3000K-5000K.

If you want really high power red or red+blue, check Flipchip Opto Duet: Flip Chip Opto |. Their PAR efficiency is lower than white COBs, though. From my brief communication with them, they don't seem to be targeting right, and they probably should have better understanding of plant photobiology.

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Happy Thanksgiving!

Another DIY LED update. I made a plastic container based grow space. I used Samsung H series LED linear modules this time. This module was announced in Summer 2016, but it started to ship in October. This Samsung basically beats Philips XF-3535L (I posted about this previously) in all aspects. It has amazing efficacy (187lm/W), even higher than most COB LEDs. I haven't calculated the PAR efficiency, but I'm pretty sure there is no commercially available grow light with this high efficiency. It is a bit more expensive per light output than COB, but it is easier to assemble, and better for a small area. Also, it provides very even light distribution. It costs about $60 to cover 2-3 sq. ft.

I built this for pygmy Drosera, so it is targeting high-light plants. But if you increase the distance or spacing, it will work with orchids, too. I listed an alternative configuration with lower output. It takes about 1 hour to assemble.

Here is the link to my Orchid Borealis blog post.





Drosera dichrosepala ssp. enodes from Scott River. Catalogue #10a of Drosera Gemmae.

[MrEvolution]

I'm still a bit confused.

SMD vs COB

Which LED tech is suggested for growing Vanda, Oncidiums, Dendrobiums??

Was just using a standard 3000K A19 60W replacement inside a recessed light fixture. The plants were kept at a distance of 20" - 36" from light source. The reason was just to hold them over until spring came around again.

But have been dealing with pest and fungus gnats and no longer willing to take them out again this year for the short summers in NYC.

I see those 3xRED/1xBlue 5050 SMD on Ebay Red 660nm + Blue 455nm 5:1 LED 5050 Flexible Strips Light Plant Grow Aquarium | eBay and was thinking if I ran at least 2 strips across a 4ft would be sufficient light?

or COB type lights be more efficient at 3000k CXB3590 type LED work much better??

Need some help with this lighting setup for money well spent. Thanks for the help.

I've access to plenty of PC heat sinks and fans.

MY setup is a open wire rack 48" x 18" x 72" with one shelf dividing the rack space.

[Ninly]

I'm new here, hope it's not inappropriate to reply in-thread like this!

A few weeks ago I went looking for information about building my own LED fixture for my orchids -- I already had some Phals that were doing OK with natural light, but had recently acquired some new plants that I expected to require more light than was available. That's when I found this board, and this post:

Originally Posted by naoki

Another DIY LED update. I made a plastic container based grow space. I used Samsung H series LED linear modules this time.

Naoki, thanks for your blog and your detailed explanations of the LED circuits and drivers! I'm a ~bit~ handy with that stuff, but hadn't worked much with LEDs or constant-current drivers. After considering a few possible configurations (longer LED strips) I ended up following your grow-bin design more or less exactly, except modified for a adjustable-height shelf fixture instead of a bin like yours -- which involved just a couple more pieces of C-channel. I plan to build another just like the first -- allowing for future orchids (yes please!), and/or for seedling starts for the garden.

Here is a gallery of the construction process: LED artificial lighting (after design by orchidborealis.blogspot.com) - Album on Imgur

[naoki]

Originally Posted by MrEvolution

I'm still a bit confused.

SMD vs COB

Which LED tech is suggested for growing Vanda, Oncidiums, Dendrobiums??

Sorry for the late reply, I didn't notice the post...

For a given efficiency, COB will be cheaper (i.e. it will produce more light per cost). The other consideration is the shape of the grow area. With Vero 29 Generation 7 (which would be my current choice of COB) at 50W ea, you will need about 4' between the floor of the grow area to the place where you put the light. So it is not so great for shelf type set up. You can use many smaller COB LEDs (like Citizen 1212), but then you need more of them, so it takes longer to make the fixture. If you have shelf-type set-up, those linear modules with mid-power LEDs (Samsung H series) would be great. Linear modules are easier to assemble.

Originally Posted by MrEvolution

Was just using a standard 3000K A19 60W replacement inside a recessed light fixture. The plants were kept at a distance of 20" - 36" from light source. The reason was just to hold them over until spring came around again.

If you have enough of them, plants would grow. But PAR38 type (directional, flood light) might be better than A-type (round bulb). But the efficiency is about 1/2 of high-end COB or linear modules.

Originally Posted by MrEvolution

I see those 3xRED/1xBlue 5050 SMD on Ebay Red 660nm + Blue 455nm 5:1 LED 5050 Flexible Strips Light Plant Grow Aquarium | eBay and was thinking if I ran at least 2 strips across a 4ft would be sufficient light?

or COB type lights be more efficient at 3000k CXB3590 type LED work much better??

I'm guessing that you are talking about the ones which you can cut into desired length, and they use 12V or 24V constant voltage power supply. You can grow plants with them, but it is waste of money in most cases. Due to the design, I have never seen an efficient LED tape. So even if it is given to you for free, it usually become cheaper to buy a quality LED within a year or two (depends on the cost of electricity, but I'm guessing NYC isn't too cheap).

Originally Posted by MrEvolution

I've access to plenty of PC heat sinks and fans.

MY setup is a open wire rack 48" x 18" x 72" with one shelf dividing the rack space.

So is the height of each shelf is about 35", and you are growing fairly tall plants? You can go either COB or linear module. But if you can afford, linear modules are easier and give nice homogeneous coverage. 3 strips per shelf will provide light for the relatively high light orchids which you are growing. 2 per shelf might work, but with the height, it may be a bit at the low end.

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Originally Posted by Ninly

Here is a gallery of the construction process: LED artificial lighting (after design by orchidborealis.blogspot.com) - Album on Imgur

Looks great, Ninly! And cute kids! Thank you for sharing your project. H-series comes in 2' and 4', so 4' strip could be handy for your kind of shelves. But I've heard that the longer one is a bit more tricky to attach to the C-channel because it might not be completely flat. If you need, I can check which drivers work with 4'.

I see you have planted aquariums. I'm making the aquarium hood with Samsung H-series at this moment.

[Ninly]

Thanks again! The kids had a lot of fun with it.

Originally Posted by naoki

H-series comes in 2' and 4', so 4' strip could be handy for your kind of shelves.

I strongly considered designing fixtures with 2- or 4-foot strips. I suppose the main reason I didn't was that it made it really easy to just copy your wiring for my first LED project, and not have to worry about figuring out which drivers would work with the other units. But there's also the advantage that we will be able to hang and adjust the height of two fixtures separately (though we could also have done this with 2-foot fixtures). This will be especially handy for starting seeds for the garden.

Originally Posted by naoki

I've heard that the longer one is a bit more tricky to attach to the C-channel because it might not be completely flat.

I actually had a minor challenge here. I ordered a tube of thermal compound that is described as being more adhesive than the typical silicone grease -- but it was shipped from China and still hasn't arrived. I used an old tube my brother had lying around, and the strips on the ends of the fixtures both tend to fall out where there isn't wiring to hold them in. They do have a slight concave shape. I just used scrap pieces of wire to make "clips" around the C-channel, gently clamping the PCB in place.

Originally Posted by naoki

I see you have planted aquariums. I'm making the aquarium hood with Samsung H-series at this moment.

Funny you should mention! I ordered 10 of the Samsung units to qualify for the first bulk discount -- giving me enough for two shelf fixtures and one smaller light "hood" for the 10-gallon tank. As you can see in the photo, I've just got a CFL in a clamp light sitting on a glass top for now -- I plan to just replace that with two more 1-foot LED strips on the same kind of circuit you have (with one strip per parallel branch).

I'll be very interested to see your hood! One of my eventual goals is to design and build a light for the larger aquarium with Arduino-controlled color modulation and dimming. Someday -- it will take more time than I have handy at the moment!

[naoki]

I've been very happy with Samsung H-series (see post #51), but there is an improved version announced at the end of Aug. 2017. It is called Q-series. Very similar to H-series, but about 10% (actually more like 8%) increase in efficiency. Now it exceeds 200 lm/W at the nominal current! In comparison, typical house-hold LED bulbs or LED shop light you can get from Walmart etc. are barely 100 lm/W. The price is similar to H-series. It is more limiting in the driver selection than H-series, though. I've added possible drivers for the new Q-series in my previous blog post (scroll to the very end).

As a different note, which I have forgotten about, I was curious about the longevity of those cheap eBay 100W COB LEDs (the ones in the very beginning of this thread). So even though it is cheaper to replace it with a high quality COB, I kept one running. It lasted 3 years with 13h/day. It was driven at around 45W, I think. It lasted shorter than Cree, but it lasted longer than I expected.

[Nexogen]

I have moments when I get crazy (age), I will use (in one terrarium) Samsung Q-series + 660nm (the problem is that in data book is not given the spectrum and I do not like stretchy plants - some say that shade avoidance is actually created by green) I think this is the best solution (for the moment - after the green light theory).

[naoki]

You have to look at LM301B data sheet here to find more detailed info like SPD.

[Nexogen]

Originally Posted by naoki

You have to look at LM301B data sheet here to find more detailed info like SPD.

Thanks, it's normal, some LED manufacturers produce without much 450nm to avoid disruption of the circadian cycle.

Just as an idea, here is a heatsink that goes to the Q-series.
Aluminum Heatsink Cooling for 4 x 3W LED, LED Bulbs - Amazon Canada