Biggest LED COB yet.

I have bought a couple of these 70w LED panels since you’ve posted this video. I have noticed that some of the panels show really poor LED matching, while some show incredible matching. There are two things I have found all of the good panels share; they were all bought by USA sellers (I live in the US), and they had a solid green band along the bottom (solder points are to the left,) along with a brand name of any sort along the bottom center. Just to pass the information along...

Cheers Clive, I just ordered 3 off eBay from China, I'll give that a try when they arrive..

Gordo

Simplest approach might be to use a 12V supply and resistor to get the maximum desired current and then use the PWM controller to adjust down from that.

Big Clive

Thanks Clive!! These are the very dab for my workshop, mounted on the underside of the shelves above my bench - nice & bright and presumably the large area = diffuse light. Currently I have self-adhesive strips of 12V 5050 white leds (which look cool but are nowhere near bright enough). Because the strip includes series resistors for every few leds, a cheap eBay pwm controller gives fairly uniform 0-100% brightness variation as I turn the pot - that's not going to work here. I think I need a variable current source - 0-1A or 0-1.5A based on your assessment of the brightness. I'm wondering if you can think of anything off-the-shelf (and cheap of course) that would do the job - there are plenty constant current LED drivers on eBay but I don't see any that offer adjustable current.. Any advice greatly appreciated..

Gordo

Gotta have some of those! Mmmmm... The light...

I'd have to use a proper CRI meter to get an accurate result. The panel I've got is also a warm white one, which is less ideal for filming.

Big Clive

Any chance you could compare the output of this next to the Yuji High CRI LEDs? I'm very tempted to get some of these for little lighting effects on high speed macro cinematography but my gut is it's all too good to be true and the CRI is trash.

The phosphor is in a gel that is flooded around the LEDs and would damage them by ripping off the bond wires if an attempt was made to remove it. They probably will do a blue version at some point, where the phosphor gel is replaced by clear gel instead.

Big Clive

Guess I should have watched all the way to the end before posting. :p I wonder if some sort of solvent (acetone, perhaps?) would dissolve the gel without hurting the LEDs...?

Daddy Bearcat

Guess I should have watched all the way to the end before posting. <. acetone="" gel="" hurting="" i="" if="" kind="" leds="" of="" perhaps="" remove="" solvent="" some="" the="" without="" wonder="" would="">

Daddy Bearcat

How about mounting one behind a front license plate that flips around James Bond style for off-road vehicles to use while...you know...off road?

Michael Thompson

So are those UV LEDs with a phosphor-coated panel in front...? If you could get the panel off, it might make a nice exposure light for etching PCBs and things.

Daddy Bearcat

Clive you rock. Plain and simple.

Michael Thompson

Thinking I might pick a couple of this COB's. Use a discarded 4' fluorescent light housing and hang above my work bench. I'll need to come up with power supply. -thinks intently...

YouTube has been experiencing burps from time to time. It's just part of being such a massively huge content delivery system.

Big Clive

Found it. No need to re-invent the wheel. <a href="https://www.amazon.ca/gp/product/B01N1MIBS6/ref=ox_sc_act_title_1?smid=AA7JUKO286HFR&amp;psc=1" rel="nofollow noopener" target="_blank">https://www.amazon.ca/gp/product/B01N1MIBS6/ref=ox_sc_act_title_1?smid=AA7JUKO286HFR&amp;psc=1</a>

Anyways, I'll find a solution via Bluetooth, even if I have to write an app to do it via the camera2 API.

This is what I don't get. You have the camera mounted on top looking down, but when you go to adjust something, your arm moves to the right as if you have a device to your right that you can do this with.

For some reason the video won’t play, “try again later”, YouTube says. Other videos plays fine still... I will try again later, just wanted to mention it in case other people experience the same.

Robert K

For low power use you could use some resistors to limit the current. A 1 ohm resistor rated about 3W or higher would work. You could switch between resistors to vary the output from working light to ambient or night light.

Big Clive

A full G4. Open camera is an app that gives better control over the built in camera if the manufacturers firmware/hardware allows it.

Big Clive

Thanks for the quick reply. Isn't that an Android app? Don't you need another android device to control it? I am not clear. I thought you use the G4 play to take the videos! Its not a problem for me. I have an android tablet which I could use. I just wanna make sure I am not going down a dead-end street. Thanks again Clive.

I use the on-screen controls of open camera on my Moto G4.

Big Clive

I asked you what you use to zoom and control your phone camera in another comment but I guess you didn't see it. Can you tell me what you use? There are a number of BT devices but I am not sure what to buy. Thanks.

Wow that's quite a COB. I wouldn't mind putting some of those in my motorhome to replace the old fluorescent fixtures. How you best go about regulating the supply down to the more manageable output that 10.5v-11v gives you from a varying leisure battery voltage of 14.4-12.3v? Would you just put a resistor in series or something more complex?

Jimmeecee