Holy Japanesie lemon squeezy driverless COB

[Gree N]

So great advancements have come in lighting since Thomas Edison or should we say Nikola Tesla's light bulb idea.
Now the focus is on COB's (chip on board) as LED's aim to take their share of the 100 billion dollar lighting market.
There are a lot of companies striving to lead the LED market like Cree, Lumileds, Vero, Epistar plus many more.

Now we see the emergence of COB's with integrated drivers which can run off 110v or 220v and also the smart ic chips which run driverless where they light half the cob as the currant runs in and the other half as the current returns too the source. It produces a flicker not visible by the naked eye similar to a fluorescent light. I'd love to hear your opinions on these cobs apart from the obvious that we are dealing with live mains so they shouldn't be worked with if one is not competent too do so.

I've ordered some 30w and 50w integrated driver chips and also 50w smart IC chips in warm white and cool white. Also have some 50w full spectrum chips on the way.
I'll be setup with a multi-meter, light meter and thermal gun for testing as well as a good circuit breaker ..

 

[Justwannagrow]

Do you have a link to those smart chips

 

[stage4]

Am I missing something or are these a great and cheap option.
UK eBay item number: 272387289292

10 off these give a combined total of 1500W and 150000 lm ! for £85.99
No driver, 220v/110v direct. I assume I could connect 10 of these to a single wall socket ?
I also assume 10 off these in Cool White would be ok for veg and flower ?

btw I am new to this LED hunt and can`t pull the trigger on buying a CXB3590 COB or equivalent setup.

 

[Justwannagrow]

Well how would you power it, I doubt it has cord sticking out of it to plug into something. You need to find a datasheet on it

 

[stage4]

There a pretty good review here

He also mentions the ability of adding a triac dimming chip to the circuit.
But yeah connects with Soldered joints !! the heat sink would have to be good.
I have ordered 2 of them so will let you know how it goes.

 

[Gree N]

I have ordered a bunch of these running from 30-50w each I ordered a range of cool white, warm white and full spectrum. When I get them in the mail and wire them up I'll post some photo's.

 

[stage4]

That`s cool, the more info the better.

You know, I get when some guys say `buy expensive and buy once` but I guess this is the cheapskate in me,
I have also ordered a bunch of parts.
I have a Mars II 900W which have vegged my 1st grow and which has now done week 2 in flower.

I got 3 plants shoved together under the light and what I was hoping to do is -
Imagine a spider, where the mars II is the body, I want to attach bendable legs that have separate LED chip and fan holders that can be moved independent of the main light.
No more rotating the pots to share the light and prolly confusing the hell out of the girls.

Here`s some stuff I am waiting to try.

 

[Canresearcher]

hmm, just reading this and I am very concerned. LEDs must never be directly driven from mains as doing so leads to destruction pretty much instantly. LEDs are designed for DC only.

smart ic chips which run driverless where they light half the cob as the currant runs in and the other half as the current returns too the source.

A driver acts to #1 convert the AC to DC and then keep the current at a specific level so as to not burn out the LEDs in the array. I'm not sure about what you mean by returning to the source since you're not generating any electricity.
I would stay far away from those large panel LEDs as possible as the are quite often full of dead emitters. The high output crees are a better bang for the buck.

 

[Gree N]

These LED's have specialised drivers built for the LED's which that they power and they are built into the chip itself. So the mains are connected to the driver then the driver powers the LED's through a circuit printed into the chip.
It's the next step in technology and I'm sure we will see Cree, bridgelux and vero heading in the same direction in no time, there probably just waiting until old stock is sold off before they switch.

 

[Canresearcher]

The integrated chip idea is neat but it has some setbacks especially at higher powers. This is more suitable for many tiny LEDs in a larger array (or as a module as suggested by Philips lighting division). This is where inside lighting will be going.

One big limiting factor is the cooling need for the larger emitters (XLamp CXB3590). Those drivers MUST be kept separate
as heat from the diodes is sufficient to cause the resistance to change in the LED die. The BUCK driver is continuously adjusting/regulating current to match the change in resistance due to heating.

 

[Gree N]

The integrated chip idea is neat but it has some setbacks especially at higher powers. This is more suitable for many tiny LEDs in a larger array (or as a module as suggested by Philips lighting division). This is where inside lighting will be going.

One big limiting factor is the cooling need for the larger emitters (XLamp CXB3590). Those drivers MUST be kept separate
as heat from the diodes is sufficient to cause the resistance to change in the LED die. The BUCK driver is continuously adjusting/regulating current to match the change in resistance due to heating.

Yes they need to be cooled sufficiently that is a given....
I don't think they MUST be kept seperate, there's many different cooling options you could go with.

 

[Mayne]

I seen a setup for $14 usd, 50W driverless with fan-heatsink, plugs, lens and holder. Be good even for houseplants and such, and low power. Might get a few for supplemental. can simply change out the cob for any size under 50W.

 

[Maximo]

I'm making my 3rd panel with driverless COBs, each one is 200watt (50w times 4 chips).
They are super bright LEDs, so they must have a great power conversion factor.
The downside is the grow chip spectrum ones don't last long, at least not the ones that I got.

 

[Canresearcher]

Pls Update

Hmm, just saw this post..

I'm a little perplexed here. LEDs should be lasting at least 20K -40K hrs of use (minimum). If these "so-called driverless" LEDs aren't lasting I suspect they're being way over driven or they are cheap copies.


I should strongly warn anyone buying off Ebay that there are many component warehouses dumping fakes on the market via PRC (China).. There have been many people getting fake high power LEDs, driver boards, Electrolytic capacitors..etc off ebay for what seems like a great deal only to discover sooner or later that the product unexpectedly dies. Integrated LEDs are one such item that is being faked. NEVER buy any component off ebay unless you can get a manufacturer verification certificate.

An honest review of the "driverless" LED below:

The term driverless is erroneous, they have an integrated driver on the PCB. They really should be referred to as an integrated LED.

What are you using as TIM (thermal interface material) ?

Have a look at this "driverless LED"
Note the outside of the LED is populated with ICs, transistors and a miniaturized transformer.
This is what is known as a "buck driver". Also on this board is also a FBR so that the board can be used on AC.

StackPath

 

[Canresearcher]

In the below video during the teardown of these "driverless" LEDs it is mentioned that integration of the LED area with the driver creates some very real power regulation problems. As the driver ICs heat up, the ICs can no longer regulate power efficiently this means there is a very real risk of over currenting the LEDs. Another problem seen on these cheaper "high output driverless LEDs" is the complete lack of AC line filtering. There is an FBR on the board that converts AC to DC, but there is still transient AC getting to the ICs and to the LEDs.. This is a sign of a very poor design. This would have been prevented by a simple electrolytic capacitor across the inputs.

As I will restate, if one buys off Ebay one should really be careful about fake or copy products.... Ebay is flooded with them.

 

[Maximo]

Yes you're right, "transient AC getting to the ICs", may be giving them a short life of a couple of months.
I have 8 x 50 watt chips operating at the moment. Out of them two grow chips burned out and one warm white, over a period of three months.
Just in case it's just a thermal issue, I've changed over from cheap 'heat sink plaster' to proper heat sink compound, so far so good.

 

[Canresearcher]

Yes you're right, "transient AC getting to the ICs", may be giving them a short life of a couple of months.
I have 8 x 50 watt chips operating at the moment. Out of them two grow chips burned out and one warm white, over a period of three months.
Just in case it's just a thermal issue, I've changed over from cheap 'heat sink plaster' to proper heat sink compound, so far so good.

There are several (possible) reasons for the failure.
1# You need a filter cap across the input (100-110uF) after the rectifier. Be very careful about how large a cap you get.

2# Crappy silicone insulation

get off all the crappy silicone insulation. This just traps heat in and creates problems. sink each IC with mini-ram cooler copper sinks. (it's a crap shoot but it might work)

3# Your burn out is likely a combo of (LEDs being over driven + AC ripple + heat). Find a way of measuring the current draw from each LED. You'll notice the draw is higher once on, then the draw will sag as the diodes heat up. You want to at least 1/2 the current so that the there is minimal sag. Insert a 1.5Ohm resistor on each diode string if you can.


This gives some idea about why these cheap LEDs are failing. Please take note.. another reason to build your own from scratch.

A typical LED will have a spec that represents a typical point along the operating curve. That would look something like “3.3V @ 20mA typical.” Driving this LED above that point will shorten the useful life. You may also get a maximum rating for either current or forward voltage. Exceeding those ratings will dramatically shorten the useful life, generally ending it suddenly in the process. But driving an LED “hot” will make it burn more brightly for a shorter time. The heat dissipated by the junction has to be conducted through the leads, which aren’t very big and aren’t designed to heatsink the package. When the junction runs hot, the light output will also degrade much more rapidly. You may find that your LED won’t light up at all without being overdriven somewhat. If the package of an indicator LED (the 5mm or 3mm types) feels hot, you are definitely overdriving the LED. Illumination-grade LEDs are designed with heat sinks in the package, and it’s normal for these to run hot. The 1W dissipated by the Luxeon Star will warm up a heat sink quickly at room temperature.

Then there’s thermal runaway. The current through the junction will tend to increase as the temperature rises; so current-regulated drivers are preferable to voltage-regulated drivers. But proper thermal management is important too.