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What Happened to the 100000 Hour LED Bulbs?

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Re: What Happened to the 100000 Hour LED Bulbs?

#261

Post by dreamcompiler »

bombela wrote: post #197
dreamcompiler wrote: post #124

Earlier quoted context omitted.

I've started doing this. Bought a large panel fixture and a separate high-quality LED current source and it has been absolutely great. Next time I build a house I'll probably run all the lighting circuits on a hefty 24VDC main power supply with small DC/DC regulators on every fixture. There's no reason nowadays why lighting circuits should be 120 or 240VAC.

power loss and price of copper is a good reason to bring 120/240vac as far as possible.

Like I said in a previous comment, with LEDs, power requirements are small and distances within a house are small. Coupled with a resonably high but safe voltage (like 24 or 36VDC), there's no reason why 14 gauge copper wire couldn't work just fine for a lighting circuit.

Re: What Happened to the 100000 Hour LED Bulbs?

#262

Post by phasetransition »

jandrese wrote: post #217
phasetransition wrote: post #105

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?

All bulbs produce heat, both from the LEDs and the electronics. Incandescent bulbs were blazing hot, too, and they radiated IR on top everything else.

A high efficiency LED assembly is still producing on the order of 50% light and 50% heat.

Re: What Happened to the 100000 Hour LED Bulbs?

#263

Post by sleavey »

jandrese wrote: post #217
phasetransition wrote: post #105

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?

I think they might have began quoting the LED lifetime on boxes, which is still true, but in reality something else in the bulb usually breaks before the LEDs themselves. I guess manufacturers have either taken it upon themselves or have been forced to reduce the quoted lifetime since the famous 100,000 hours marketing.

Re: What Happened to the 100000 Hour LED Bulbs?

#264

Post by rmu09 »

ip26 wrote: post #130
dsfyu404ed wrote: post #122

Earlier quoted context omitted.

>Look on the bright side- in terms of real power, the electric oven, vacuum cleaner, AC compressor, and fridge compressor totally swamp the entire load, waste and all, of those 5V devices. This isn't an appropriate comparison. Those appliances actually do useful things that need to get done so the energy isn't just wasted like it is with power supply inefficiency. Sure a 12vdc circuit would be nice. It wouldn't be ni…

The point is the power delivery system we have does a good job for 99% of real power consumed (or whatever the number really is). I hate waste; my mains-connected smoke detectors (1% efficient) and garage door opener (15W standby) gnaw at my soul. But that's scope for improvement, not an efficiency crisis.

A smoke detector doesn't need that much power, so efficiency of the power supply is less of a concern. You have to find a useful compromise between efficiency and use of materials. Those additional components for higher efficiency need to be produced which uses resources and energy.

Although 15W standby for a garage opener seems excessive.

Re: What Happened to the 100000 Hour LED Bulbs?

#265

Post by masklinn »

iforgotpassword wrote: post #255
masklinn wrote: post #181

Earlier quoted context omitted.

They specifically mention desktop computers, not laptops.

They're basically at the same level if you don't use high end CPUs and gaming GPUs. Also see here: http://www.extremetech.com/extreme/135719-5-9-watts-the-worl... - tldr: 30w idle for an unmodified average system. Mind you this was 2012, mid range systems surely haven't gotten more power hungry since then.

> Also see here: http://www.extremetech.com/extreme/135719-5-9-watts-the-worl.... - tldr: 30w idle for an unmodified average system.

That's an order of magnitude more than an idle laptop.

And they're not talking about any sort of "average system" they're ballparking a "reference desktop" which tops out at 150W under load, that's not just "don't use a gaming GPU" that's "don't use a GPU at all". And if you're building a "desktop computer" with an APU and an SSD… why are you building a desktop computer?

Re: What Happened to the 100000 Hour LED Bulbs?

#266

Post by masklinn »

telchar wrote: post #248
mrb wrote: post #235

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…

Perhaps dimmable LED bulbs would be better in that regard? The LED dimmers on the market use a very high rate PWM (afaik) to prevent/minimize flickering at low brightness. I would guess that the dimmable bulbs are designed to work well with intermittent power and so wouldn't have the same problem. Of course it's still hit or miss, compatibility between bulbs and dimmers seems to be very hard to judge without testing…

The bulb they link are listed as dimmable (flicker-free silent dimming) aside from the part they quoted.

Re: What Happened to the 100000 Hour LED Bulbs?

#267

Post by manmal »

mrb wrote: post #235

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 only buy Philips bulbs for this very reason, or from brands that advertise being flicker-free. With iphones, slow motion mode also makes the flicker very visible without the need to transfer to a PC.

Visible light impulses influence brain wave patterns (e.g. [1]), and it might not be beneficial to look at pulsed light with a frequency that is not well researched.

Same thing with screens, most LEDs are dimmed with pulse width modulation [2], so they flicker at most brightness levels except the very brightest one. Some iPhone X users claim they get a headache when looking at the phone at the lowest brightness setting (OLED is even worse in that regard than LED, IIRC).

1: https://clinicaltrials.gov/ct2/show/NCT03657745 2: https://www.eetimes.com/document.asp?doc_id=1281013

Re: What Happened to the 100000 Hour LED Bulbs?

#268

Post by slow_donkey »

mrb wrote: post #235

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…

Never even thought about this problem, thanks for bringing it up

Re: What Happened to the 100000 Hour LED Bulbs?

#269

Post by jpalomaki »

As pointed out in the article the LEDs just fade away. This means that if you define "lifetime", you also need to define how much you can lose brightness to still considered it to be alive.

Could it be that with the initial 100k LEDs the definition was different than with current ones? As mentioned, the industry is now using the 70% of brightness as the limit. Since such figure was probably not defined early on, maybe the vendors put the limit much lower.

Re: What Happened to the 100000 Hour LED Bulbs?

#270

Post by mrb »

telchar wrote: post #248
mrb wrote: post #235

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…

Perhaps dimmable LED bulbs would be better in that regard? The LED dimmers on the market use a very high rate PWM (afaik) to prevent/minimize flickering at low brightness. I would guess that the dimmable bulbs are designed to work well with intermittent power and so wouldn't have the same problem. Of course it's still hit or miss, compatibility between bulbs and dimmers seems to be very hard to judge without testing…

In my experience, dimmable bulbs are no better. Most of them still suffer from the 120 Hz strobing effect. That's because even though they might PWM at 1-10 kHz to control the dimming function, when A/C voltage crosses zero, the "on" state of the PWM can still be a lot dimmer than the "on" state during the A/C voltage peak.
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