So, engineering lead of a (outdoor) led Luminaire manufacturer here. And our sales director used to work for one of the biggest Asian light bulb OEMs. Happy to answer specific technical questions out there that this article triggered.
If cost were less of a concern, what engineering changes would you make to the bulb?
#1 more die. More die means less current per die, which helps efficacy in a nonlinear way (google "LED droop")
#2 better passives. Aluminum polymer caps, for instance
#3 lower temps, in however you want to achieve that aim
#4 some TVSS element if there wasn't one already
Article does not so much as mention Philips which are the gold standard here. The off brands he’s looking at are the problem. Cree is a fine brand for LED components but not for the entire bulb assembly in my experience.
yeah, darn those pesky laws around liability getting in the way of some good old-fashioned handiwork.
The law once mandated that you hire the services of a licensed electrician to replace a lightbulb. Imagine if the same laws where applied to tech. Need to update Microsoft office? No way arround it you need to hire the services of a licensed IT professional! You might get electrocuted in the process not being a professional. So it all makes sense.
Cite please. Was that ever really a law anywhere other than Victoria, Australia?
So, engineering lead of a (outdoor) led Luminaire manufacturer here. And our sales director used to work for one of the biggest Asian light bulb OEMs. Happy to answer specific technical questions out there that this article triggered.
So, why do LED bulbs seem to last not as long as they should?
I think the parent article provides a reasonably accurate description of why
In some of the fixtures in my house, I've thought of installing small fans running at low speed (resistor in series with the fan slows it down) to stir the air and help cool the lamp.
you can power an entire floor's worth of lighting ? Must be either very low current lighting or that's some pretty beefy Cat6. I think the average Cat6 cable is only 24 gauge and that won't carry a lot of current very far.
Star topology
Isn't this like saying you could light the world if you had a big enough switch and unlimited cable?
So, engineering lead of a (outdoor) led Luminaire manufacturer here. And our sales director used to work for one of the biggest Asian light bulb OEMs. Happy to answer specific technical questions out there that this article triggered.
Since the article never answered the question, do you know what happened to the 100k hours LED bulbs? Were the initial estimates just over-optimistic? Was it all marketing hype?
I've taken every single LED bulb that has failed on me to pieces and it's always the same failure mode. The heatsink compound isn't applied properly to the back of the LED board. The LEDs immediately in the gaps smoke out. Alas this isn't a problem. If a lightbulb goes, Amazon send me a new one out now free of charge and tell me to throw the old one in the trash. This is one manufacturer, prevalent on Amazon, the Lon…
I replaced around 25 bulbs in my house with cheap Walmart "Great Value" LEDs just under 3 years ago and they've all been fine. Previously, I had replaced around 4 bulbs with Cree LEDs from Home Depot, and half of those were dead within a few months. The Walmart bulbs without any special pricing were way cheaper than the Cree bulbs from Home Depot, but even better, there was some sort of automatic rebate or something…
Those early Home Depot Cree bulbs were definitely defective. We bought a ton of them and have since replaced nearly all under warranty... twice. The first round they replaced with identical ones, which also quickly failed. (Always the same; started with an intermittent flicker, which progressively got more severe and regular.) More recently we've gotten a new design back, which seem better. Fortunately, after the first ones, it's been as simple as replying to the email thread and telling them how many more replacements I need!
Having an AC to DC converter at the mains to your house would be great. Using a reasonably safe 48V DC in the home seems reasonable. Modern high efficiency motor driven appliances all use internal AC->DC converters and a 3-phase DC->AC driver anyway. I'm still on the fence about what the DC voltage should be - upwards of 60-80 are still nice and require less current for a given load but you don't want your PC and TV…
PoE seems pretty nice in that regard. Easy to use, lots of appliances run on it, cabling is easy and it can carry data.
Can't carry enough current to run more than some electronics though. PoE vacuum cleaners wouldn't work.