So my ceiling light suddenly dimmed and didn’t turn bright again. I replaced the led light bulbs in there and now its alls good again.
Why do led lights not simply “burn out” or fail completely? Instead they fail by producing half (or less)the amount of light they used to. This seems like a very odd way to break. Can anyone explain why they break like this?
It’s not the LED but the cheap crap components used in the controller.
The LED bulb itself is not typically the reason that these fail. There’s also complex regulation circuitry which consists of far more complex components than a single LED. Electrolytic capacitors and driver circuits can have shorter lifetimes than the actual bulb.
With that said, manufacturers know this, so they also tend to overdrive lower cost LEDs to bring the failure rates in line with the rest of the circuit. This sounds like this may be what has happened to you just based on the dimming, but without knowing exactly how they have wired it up, it’s difficult to be sure.
I’m sorry but that’s utter horseshit. I don’t know where you heard that from but it really sounds like manufacturer propaganda. The driver circuitry won’t fail unless it’s also cheaply made and consequently running far hotter than it would if made correctly. They definitely did not spend money on a failure study to redesign the led part to match failure rates. They just did the cheapest thing possible that made light without exploding or (usually) melting.
They don’t need to run failure studies. That basic characterization work is mostly already done for you. Component vendors (should) publish tables of mean time between failure for the components you’re buying that can be used to get a rough estimation with just a few minutes of effort. Typically it’s indexed by temperature, like for caps, but depends on the part.
Now, does the bottom of the market actually use those tables? I can’t say for sure. I know one high power headlamp company does this for their LED drivers to balance lifetime with output, but I can’t know for sure what every business does.
There are multiple LEDs in the bulb and they’re overdriven, meaning they’re designed to fail. They can be modified to put out dimmer light that will last a very long time but that’s not something most people know how to or will do. Failed ones like you describe are usually repairable also but same issue that most don’t know how to or won’t.
They fail like that because one element dies entirely which messes up the circuit. If the dead one is bypassed with a small resistor the others will light back up.
Look up “homemade Dubai lamps” or as Big Clive likes to call them, “Dooby lamps”. Basically decrease the power by 30% or more by replacing or removing one of current-sense resistors to get a many times longer lifespan. Very easy with lamps that have a linear regulator on the LED board; ones that have a switching regulator inside need to be disassembled further than just popping off the plastic globe (preferrably by milling into the housing from the SMD side of the board because that doesn’t disrupt the thermal design of the LED board). With the latter approach, I can also fix another common issue: the input inductor going open circuit, usually indicated by flashing and a burned-out bypass resistor (most often 4k7 or “472”) − I just short it, I don’t care about the little extra interference if it mskes the bulb work again.
Followup question: is there a company that is not part of the new lighting cartel making screws-in bulbs that actually last 10+ years?
I have ikea LED bulbs over 20 years old.
Do you think it is possible/a good idea to DIY you own LED bulbs with off-the-shelf components?
Like hollow out a light bulb casing and put your storebought LED and controller inside
https://hackaday.com/2021/01/17/leds-from-dubai-the-royal-lights-you-cant-buy/
tl;dr yes but actually no
It’s by design so people buy more lights. It could be made to function better and last way way longer (theocratically forever by a human’s standards).
But then the quarterly line won’t go up high enough, so it’s “bad for business”.
Like someone else commented, even the bad ones can be made to at least be slightly better with small adjustments to the circuit, but then 2 people out of 8 billions around the world would be reluctant to buy the extra luxury package on their third super yacht. So obviously it’s not worth it (╯°□°）╯︵ ┻━┻
Still better than CFLs. Those used to literally burn and catch fire, and if one broke, a nice dose of mercury vapor.
