EEVblog #1343 - DEAD Deck Cree LED's

An update from EEVblog #50 (yes, #50!)
The CREE XPG LED's on the deck finally died and Dave needs a replacement, so time to hack some existing T8 LED tube lights.

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#LED #Lighting #Cree

[Bllinker]

The writers of this show are really consistent, I mean imagine writing episodes for at least the next eleven years when the series is still pretty small. Impressive! I wonder what the script will have Dave do in the next decade. I wonder how much of the lab move subplot they had at the start, those are very high on my top episode list for the whole series!

[ekkrir]

Holy **** I've been watching for this long?
I remember watching the vlog since before this came out!

[whatthefunction]

I remember that episode because I made my own just like daves!

[AndyFletcherX]

Good that you designed your installation for maintenance with nice accessible power supplies!! Well, we live and learn.

[skilledatplay]

My guess for failure would be long term moisture caused my condensation getting to the die over time. Still 7 years is pretty good life for outdoors.

[bf]

It would have been neat for a collaboration with Big Clive since lighting is his expertise!

[rocketmanprojects]

I found that thin super glue works really well for attaching LEDs to aluminum strips. Thermal epoxy is not needed. I made lots of LED strips by super gluing the 1W LEDs directly to aluminum strips. I don't bother with circuit boards, I just bend the leads up and solder wires to them. As long as the strip is mounted so it can't flex, the LEDs will stay attached and the super glue is thin enough that it doesn't effect the heat transfer. Some non corrosive silicone can be used to protect the connections.

[shango]

15 volt diode check? I must have this meter

[mscir]

Great video. I like when you explain the circuits, I didn't have a lot of analog classes so anytime you feel like explaining how the circuit works would be great. Interesting, fast paced, including data sheets and practical considerations, well done.

[kai]

Love what you're doing. You got me most of the way from "i like electronics" to automating my first washing machine to getting a development job in the industry. Thanks Dave!

[RoelofRichter]

That was my first EEVblog video, got me hooked to the channel. Started with my BEng in electronics at the time, designing a fancy modular LED lights for a subject, really helped. Thanks!

[carlg]

A few years before this was built, I believe it was Cree had switched to a new thin film technique for the active (GaN) layer in some of their most efficient phosphor-coated LEDs at the time. The thin layer was unusually susceptible to breakdown in the event of a voltage surge, and the damage was usually visible as a burnt spot on the die which of course was also a fail-short. I diagnosed some failures for fixtures which were reporting dead individual LEDs, and found that each time there had been lightning storms in the general area. At the time, it was a novelty to see isolated dark LEDs in a series array that continued to operate as normal.

[wayneholzer]

Dave's a legend learnt so much from his video's this video is helping me with a lighting led project I am working on making

[aravindhkuppusamy]

I design these LED tube light systems. 99 percent of these things are CC driven with the simplest circuit possible with minimum filters to meet the BIS's EMC standards because the manufacturing cost target for the MCPCB and the driver is <1.5$. We have used compliance voltage as high as 90V. Some of these LEDs(custom made for cheap lighting application) used in low voltage applications will have trimmed terminals to simulate series "resistance'

[crusaderanimation]

19:50 it not only work at Yankee Voltage but on Anime Voltage works too !

[neteaglek]

Any news from the custom µsupply LCD ?

[Tommyinoz]

I remember the original video for these lights. I really like the home project videos. How's the light in the bathroom going?

[mrnmrn]

Just remove the Al board from the original round heatsink and mount it on the old, thick Al sheets. The PCB can be pushed out, usually with quite a bit of force, but they are not glued (at least I haven't seen one that was glued).
Spraying some silicone spray between the board and the housing might help to lower the friction. No need for thermal glue, just thermal paste and a screw on every 10-20 cm along both sides of the PCB.
And don't forget to spray at least some clear conformal coating on the PCB, these SMD LEDs doesn't have plastic lens on them as the old Crees, it's just the phosphor in some resin, and hygroscopic, quite sensitive to humidity. And based on the level of corrosion of your old Al sheets, they used to get quite a lot of condensation out there.

[pahom]

Modern led lamps are exceptionally bad in thermal design. They are dying because of driver failure. Electrolytic caps simply dry out. None of my LED lamps have a single failed led, only dead drivers.

[billysgeo]

CREE XPG were (and are for the most part) the ducks guts of LEDs. But a bit of conformal coating, or at least a layer of clear coat lacquer