driverless LED cobs

Hi all, browsing an infamous asian online marketplace I came across driverless cob that you plug in the wall directly. Obviously with some sort of heatsink.
has anyone ever tried them with MJ?
I ordered one jsut to get a sens of how they work. Will let you know when I'll receive it.
Having said this, as I have extremely limited space to grow, I will definitely not use it on my girls for the time being.
the image shows the spec from the site. should you want the link let me know. I don't like to do advertisement.

Wall power is AC. LED's need DC. AFAIK there's no such thing as a driverless COB that plugs directly into the wall. But there it is in your screenshot: "No Driver" is one of the features.

Take a look at the spectrum. 5500K to 7000K? 7000K is almost off the visible light scale. Typically an LED or luminaire will have a specific spectrum rating. I don't know what it means when, as in this case, they quote a wide band. I suspect it has something to do with them buying whatever cheap LED's are available.

i was curious about that too, but i believe its crap(as always)

i found these here in brazil
https://e-dualcom.com.br/led-100w-branco-6000k-driverless-220vac-7575d48/

"utilizar varistor de 250VAC/10K em paralelo com o LED, assim como fusível de 1A/250V em série, para proteção contra surtos de tensão da rede elétrica"

translated to

"Use 250VAC / 10K varistor in parallel with the LED, as well as 1A / 250V fuse in series, for protection against mains voltage surges"


but theyre not cheap and not efficient, so its the same old story....

Mazer said:

Hi all, browsing an infamous asian online marketplace I came across driverless cob that you plug in the wall directly. Obviously with some sort of heatsink.
has anyone ever tried them with MJ?
I ordered one jsut to get a sens of how they work. Will let you know when I'll receive it.
Having said this, as I have extremely limited space to grow, I will definitely not use it on my girls for the time being.
the image shows the spec from the site. should you want the link let me know. I don't like to do advertisement.

Click to expand...

toss up the link,i take it its from alibaba ? i seen where someone else recently showed a similar cob that uses ac power.i cant see why they cant design a cob that uses 120v or 240v ac instead of dc.but the lifespan is 1/5th of a good dc cob.shows it at 10,000 hours vs 50,000 for a older cree

Mazer said:

Hi all, browsing an infamous asian online marketplace I came across driverless cob that you plug in the wall directly. Obviously with some sort of heatsink.
has anyone ever tried them with MJ?
I ordered one jsut to get a sens of how they work. Will let you know when I'll receive it.
Having said this, as I have extremely limited space to grow, I will definitely not use it on my girls for the time being.
the image shows the spec from the site. should you want the link let me know. I don't like to do advertisement.

Click to expand...

Yes I have seen many of them from different vendors, brands and color temps on eBay and they are super cheap. The electronics are on board the COB chip to achieve the higher voltages. I actually ordered two 50w 2700-3200 COBS for $4.11. Well, I ordered them over a month ago lol, and still haven't received them. I'm not worried, my expectations are low, if they actually ever come. I just want to tinker with stuff.

The ones I ordered are advertised at about 100lm's/w and it does state they should last 50k hours. Again, my expectations are lower than that. I mean they are like 2 dollars and a nickel a piece. To think they would "out shine", these reputable companies geared toward top quality and efficiency is just silly. No pun intended.

Anyway, haven't received them yet. I'll report back when I do and get one up and running. Tho, my experience will be basic sense I have no meters to test with tho, I may throw a few things together and use my electric meter to get a power draw reading from the wall. If it actually works. I do not plan on growing with them anytime soon.

If they don't work, I'll report back they don't work and just throw them away. Just thought I would chime in tho, I really have little to add except I have ordered them and the cost. And the long long shipping time from china to the USA.

P.S. I vaguely remember an eBay seller with the moniker or brand mazer? I don't remember for sure though.

Mellodrama said:

Wall power is AC. LED's need DC. AFAIK there's no such thing as a driverless COB that plugs directly into the wall. But there it is in your screenshot: "No Driver" is one of the features.

Take a look at the spectrum. 5500K to 7000K? 7000K is almost off the visible light scale. Typically an LED or luminaire will have a specific spectrum rating. I don't know what it means when, as in this case, they quote a wide band. I suspect it has something to do with them buying whatever cheap LED's are available.

Click to expand...

Mellodrama the driver is on the actual cob so it turns the ac in dc without needing additional equipment.
I find the idea really appealing. It will enable the DIYers to make much more elegant designs once the technology is satisfactory.
IMHO it is the way of the future unless the cob drivers are inefficient. Let's wait and see.

Mazer said:

... the driver is on the actual cob so it turns the ac in dc without needing additional equipment.

Click to expand...

Then it's not a driverless COB. I can visit my local Home Depot and fill the cart with LED bulbs that will screw right into a standard Edison light bulb socket. Every one of those LED bulbs has a driver hidden inside. So an LED bulb that screws into an outlet is not something remarkable. A "driverless" LED would be remarkable.

I don't want to get tied up in semantics, I just want to make it clear there's no such thing as a "driverless COB". I shouldn't say "there's no such thing" because maybe there is somewhere, but for the sake of our discussions, with the tech that's available to us, the statement is accurate.

And, again, 5500K to 7000K??

Seoul Semiconductor ...real company has been working this tech using AC to dc without a transformer is probably really what it should be referred to as....very inefficient in the early days, probably more or less still so....

citizen has these but im pretty sure its got an onboard transformer/rectifier of sorts

http://ce.citizen.co.jp/productse/info.php?no=112

they are small for our purposes

CobKits said:

citizen has these but im pretty sure its got an onboard transformer/rectifier of sorts

http://ce.citizen.co.jp/productse/info.php?no=112

they are small for our purposes

Click to expand...

According to the datasheets. The AC Series Citizen COBs do have an embedded alternating current driver.

AC series is the new type of LED package AC-Driver embedded in the standard COB(Chip on Board) package.
AC series does not require AC/DC converters associated with other standard COB types.

Click to expand...

I'd never heard of those AC Citizens before. Amazing. The AC COBs don't hardly look any bigger than the "normal" COBs. How do they do that?

Mellodrama said:

I'd never heard of those AC Citizens before. Amazing. The AC COBs don't hardly look any bigger than the "normal" COBs. How do they do that?

Click to expand...

Just looking at it. Looks like they added more LEDs seperate to fill out the voltage parameter. I.E., and just as an example, the large one could be perhaps 56, while they use the smaller COBs at say 12v+24v+12v+ whatever to fill in the gaps to make 110v. Not sure about the transformation of ac to dc and how that might work but. Makes sense they used more light as the resistance to equal the voltage. More efficient for a plug and play.

Mellodrama said:

Then it's not a driverless COB. I can visit my local Home Depot and fill the cart with LED bulbs that will screw right into a standard Edison light bulb socket. Every one of those LED bulbs has a driver hidden inside. So an LED bulb that screws into an outlet is not something remarkable. A "driverless" LED would be remarkable.

I don't want to get tied up in semantics, I just want to make it clear there's no such thing as a "driverless COB". I shouldn't say "there's no such thing" because maybe there is somewhere, but for the sake of our discussions, with the tech that's available to us, the statement is accurate.

And, again, 5500K to 7000K??

Click to expand...

You are absolutely right Mellodrama, and I like the fact that you want to be precise semantically. It avoids confusions and misunderstandings. But, with my very limited knowledge of LEDs I have to say I have never seen any LED like these. All I can hope for is that high end manufacturer use this method for cobs. I have attached a picture of the LED with integrated driver.
Furthermore, I asked the seller about color temp as they supply both cold and warm. Warm is 2700°K to 3200°K. Definitely not ideal but I keep my fingers crossed to see Cree start producing this sort of LED.
Peace

sixstring2112 said:

toss up the link,i take it its from alibaba ?

Click to expand...

there you go kind sir
https://www.aliexpress.com/item/COB-LED-Lamp-Chip-Beads-5W-20W-30W-50W-220V-Input-Smart-IC-Driver-Fit-For/32693479513.html?spm=2114.01010208.3.10.RsoljQ&ws_ab_test=searchweb0_0,searchweb201602_3_10065_10068_10000032_10000025_10000029_430_10000028_10060_10062_10056_10055_10054_10059_9911_10099_10000022_10000012_10103_10102_10000015_10096_10000018_10000019_10052_10053_10107_10050_10106_10051_10000007_10084_10083_10080_10082_10081_10110_10111_10112_10113_10114_10115_10037_10033_10032_10000041_10000044_10078_10079_10077_10000038_429_10073_10000035-9911,searchweb201603_3,afswitch_4,single_sort_1_total_tranpro_desc&btsid=cf741d22-8ba8-40ad-9e51-9af884d05be2

you can do it with a diode and a cap, but the chip is a diode

Mazer, thanks for bringing this up. I think you've identified an emerging trend. I'll be very interested to see what comes from the reputable manufacturers. Apparently Citizen is already there, wonder what Cree comes up with? I did some rough calculations from the Citizen spec .pdf. It looks like lm/w is roughly 80? If that's correct, the bang-for-buck will have to improve.

Is dimming possible with a COB that connects to AC grid power directly?

The ones you linked to - on the one hand, for as little as they cost why not experiment? On the other hand, they're almost surely the lowest binned units...

They never ever lasts 50.000h, this is nothing other as wishful thinking! They will probably not even hold 5.000h because of the used "low quality parts" on these PBC's. the only fact I like is they use bigger PCB's for the 70-150w COB's which give a better cooling. Reminds me a little of the new boards of Vitaly / ChillLED but with a third of it's efficacy, of course!
And the fact that they can only run at their rated power makes them even more inefficient than their driverless pondons. In addition, they can be very dangerous in case of a defect, since only a thin silicone layer protects the components.

Mazer said:

You are absolutely right Mellodrama, and I like the fact that you want to be precise semantically. It avoids confusions and misunderstandings. But, with my very limited knowledge of LEDs I have to say I have never seen any LED like these. All I can hope for is that high end manufacturer use this method for cobs. I have attached a picture of the LED with integrated driver.
Furthermore, I asked the seller about color temp as they supply both cold and warm. Warm is 2700°K to 3200°K. Definitely not ideal but I keep my fingers crossed to see Cree start producing this sort of LED.
Peace

Click to expand...

Samsung has one

http://www.samsung.com/global/business/led/products/led-engine/downlight-engine/acom

They're not very efficient, and don't safe any money.
The Citizen ones are even less efficient.

It's not worth it for growlights anyway, because you're cutting corners in areas where it's not needed.

hi all
yes they exist
yes they are AC current
yes they dont seem to need a large heatsink and because of their construction (electronic components) as the heat rises they automatically regulate themselves down...

as this guy explains and tears down one of them he explains the main problem of those lights is which is the flickering

now my question is do the flickering affects the growing of the plant and how??

The flickering is so fast that only very young eyes notice it. What I know, plants are only care for photons and if the flickering were a problem, all the PWM dimmed would have the same problem.
So no! The flicker has no bad effect, only the amount of photons counts.

Indeed, these AC COB's are self-regulating, but with a good cooling they run a lot brighter. What use is it, if they run only with 50 or 60w due to poor cooling...