411–420 of 519 posts
Lifetime isn't even my #1 concern with LED bulbs. It's strobing/flickering. I film all the LED bulbs I buy in slow motion at 240 fps with an Android phone, and play the movie back on a PC with mplayer using the dot(".") key to move frame by frame. Here is a shot I made comparing 2 brands of LED bulbs: https://youtu.be/QbenId_F2RQ (Edit: yeah you don't have to transfer to a PC, just playing back in slow motion on the…
I also have been disappointed with LED "bulbs". They get too damn hot in recessed fixtures but NOT because of the LED's. It's all because of the shitty power converter embedded deep inside the bulb getting too hot and failing. The industry has necessarily had to retrofit to where incandescent bulbs are supposed to go. I think that we'll start to see improvements in this area as people move away from "screw-in bulb" a…
These already exist. Nearly every architectural grade fixture has a separate 24VDC driver, the LEDs, and a heatsink. Here's a cutsheet for a Lithonia recessed can as an example:
https://lithonia.acuitybrands.com/products/detail/748533/Lit...
These run for $175-200 a piece. They list 70% lumen maintenance at 50,000 hours. That's 20 years at 12 hours a day for 220 days a year. Some architectural cans are a bit cheaper, some are a bit more.
Cheap LED 2x4s go for $80, pricey ones for $200.
Lifetime isn't even my #1 concern with LED bulbs. It's strobing/flickering. I film all the LED bulbs I buy in slow motion at 240 fps with an Android phone, and play the movie back on a PC with mplayer using the dot(".") key to move frame by frame. Here is a shot I made comparing 2 brands of LED bulbs: https://youtu.be/QbenId_F2RQ (Edit: yeah you don't have to transfer to a PC, just playing back in slow motion on the…
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Where did you get that? GP is talking about lighting a floor in a building.
He's talking about running a separate cable for each and every bulb. It's a wasteful solution compared to running all of the lights off of a single circuit (or limited number of circuits) like a normal building.
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This is uncommon but not rare. Have you ever seen wheel blur or other artifacting of such? It's very easy to make happen artificially under controlled conditions which means it can't be that hard to happen accidentally. Edited to add: Have you ever heard of a timing light for an engine? This works exactly the way you are describing.
The effect might not be rare but getting hurt by it is incredibly rare. Machines produce noise and vibration. Nobody is going to be fooled and try to pull a moving part out of a lathe because of some LED lighting except in the most exceptional or bizarre circumstances.
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…
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LED flicker could prove harmful or fatal if you work with anything that rotates or reciprocates. The rotating / reciprocating mass may appear stationary at some RPM. Just a reminder to only ever use incandescent or halogen lights around machinery you can touch while in operation: drills, lathes, mills, slotting machines, etc.
Just how likely is this to happen though, it would have to be the only light source and be flickering with exactly the same frequency as the machinery is traveling at (which i assume for most devices varies a lot). Not saying it can't happen but it does seem stupidly hard to achieve.
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.
Why do so many of the bulbs run hot? Like so hot you can't hold them in your hand if they were on when you unscrewed them. Isn't this a lot of wasted energy?
Lifetime isn't even my #1 concern with LED bulbs. It's strobing/flickering. I film all the LED bulbs I buy in slow motion at 240 fps with an Android phone, and play the movie back on a PC with mplayer using the dot(".") key to move frame by frame. Here is a shot I made comparing 2 brands of LED bulbs: https://youtu.be/QbenId_F2RQ (Edit: yeah you don't have to transfer to a PC, just playing back in slow motion on the…
I can spot a Cadillac or GMC vehicle on the road a mile behind it from the flicker of the taillights. It's terrible.