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There's something off about LED bulbs

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Re: There's something off about LED bulbs

#801

Post by petrocrat »

Zak wrote: post #533
cogman10 wrote: post #222

Earlier quoted context omitted.

This is the frustrating thing about LEDs that IDK we can change. If there was a "DC" light socket in the house we could have LEDs outlasting owners, and for cheap. Nearly all the expense of LED bulbs is the power supply. Everything else is dirt cheap. A single home DC power supply with ~200W of output could light an entire house, flicker free. What's even more frustrating is I think we could fix it. A national regula…

Trying to cram all the infrastructure for an LED lamp into the shape of a light bulb is a bad idea, even if the input power is DC. Good designs for LED lighting have larger surface areas for heat dissipation and some physical/thermal separation between the LEDs and the power supply. A quality power supply does not produce flicker. As other comments have noted, dimming, or even predictable output requires some sort of…

Probably going to sound crazy, but we could start running water pipes in front of the walls and under the ceilings and mounting the LED's directly on the pipes for cooling. Creativity, thinking wholistically... the entire contemporary western house design needs a rethink frankly, from DC circuits to electrification to modular, mass-produceable utility drop-in pods, all with an eye towards integrated systems design paired with scalable modularity.

Re: There's something off about LED bulbs

#802

Post by charrondev »

b112 wrote: post #275
amluto wrote: post #74

Earlier quoted context omitted.

> The same light quality is vastly more expensive to achieve with LEDs, even if you account for high electricity prices. In a screw base, maybe. But compare: https://www.digikey.com/en/products/detail/luminus-devices-i... $25 for an excellent 700mA driver, 86% efficient. https://www.digikey.com/en/products/detail/bridgelux/BXRH-30... $3.45 for a very nice, ~2000lm 97 CRI LED, about 99 lm/W. (Efficiency goes up quite…

https://www.hydroquebec.com/data/documents-donnees/pdf/annua... Sadly, with San Fran anywhere from 4.5x, or more than where I live (Quebec), and with LED products lastly barely longer than incandescent bulbs, it is typically a loss. Maybe a 5 year warranty on LED bulbs should be a law, to ensure better quality control and build. The competitors can compete around that requirement.

To be fair in Quebec we have what is probably the cheapest electricity cost in all of North America.

I’ve had the dimmable coloured hue bulbs for a while and while expensive I can say none have ever died on me in ~5 years. Certainly no flickering.

Re: There's something off about LED bulbs

#803

Post by peanut-walrus »

So much of the problem with LED lights is from the integrated power supplies. Why is it not more common by now to just wire up indoor lights with 48v DC supplied from a PSU in your wiring cabinet and the lights can be just plain LEDs? Lower overall cost, more reliable, safer.

Re: There's something off about LED bulbs

#804

Post by jandrese »

JohnFen wrote: post #198
DougN7 wrote: post #135

Earlier quoted context omitted.

This is just an anecdote, but I’ve had multiple “10 year” LED bulbs fail after just a year or two. I suspect much of the claims for these bulbs are theoretical as they just don’t hold up, probably for reasons the grandparent poster is pointing out.

Almost all LED bulb failures are because the power supply died due to overheating, not the LEDs themselves. I harvest the LEDs out of dead bulbs to use in hobby projects. With Edison-style bulbs, anyway, the orientation they're mounted in makes a huge amount of difference. They're last a lot longer if they're oriented upright (base down) than in any other orientation because it reduces the heat buildup in the power s…

Sometimes it is the power supply, but I've also had a number that died simply because one LED burned out and failed open. Because they are wired in series it only takes one failed LED to take out the entire bulb. If you're a cheapskate you can sometimes get a bulb working again by testing the circuit and bypassing the burned out LED with a jumper wire.

If the bulb dies but you notice that all of the elements are still just barely on (like a dim spot of light in the middle of each one) then that's a good indication that you have a dead LED.

Re: There's something off about LED bulbs

#805

Post by vl »

jghn wrote: post #739
vl wrote: post #611

Earlier quoted context omitted.

You can't buy a bulb that is rated to last a lifetime, but you can buy ones rated to last for 10+ years if used 8 hours a day (i.e. 35,000 life hours). I retrofitted entire house - 200+ bulbs and fixture retrofits more that 5 years ago. I had one or failures since. I bought highest CRI bulbs, i.e. most expensive, and they work well. (Also, do not use bulbs for downlights - get entire "led can light fixture retrofit")…

> 35,000 life hours How trustworthy is that state though? I have always assumed 0% trustworthy. Is that incorrect?

I don't think it's untrustworthy in a sense you are deliberately lied to. I think more likely problem is that there is quality control issues and entire batch of particular bulb is compromised, like can happen with anything else - hard drives, RAM, pencils.

In general it's quite reasonable. Cheaper bulbs failed on me, more expensive ones work just fine for many years.

One thing is I wonder about if phosphorus (or whatever chemical they use) is burning out over the years. I.d. do I get worse light quality as these bulbs age?

Re: There's something off about LED bulbs

#806

Post by Dylan16807 »

pwg wrote: post #648
zaroth wrote: post #358

Earlier quoted context omitted.

Cars are starting to move to 48V DC. My under cabinet lighting in the kitchen are powered by DC from a power supply in the basement. I could definitely see this becoming more common. Powering the ~100 watts of fixed lighting spread across my whole house on ten different 15A 120v circuits, each with their own arcfault breaker and 12 gauge copper electrical lines running back to the panel is fabulously expensive for wh…

> but that’s problematic when the next owner tries to screw in a standard bulb - what happens when it sees 48V DC? If by "standard" you mean a incandescent tungsten filament bulb, nothing at all. For a true LED driver power supply, it would be constant current, so the tungsten filament would see 25mA (or whatever the constant current is set for) of DC, and nothing bad would happen (the filament also would not likely…

48V without a current limit shouldn't be nothing, but you should expect less than 10% brightness.

For constant current, you'd need to drive at least 9 watts so it would be more like 250mA if not higher.

A 1600 lumen LED module might take as much or more current than a 60w incandescent. If your constant current supply can output between 0 volts and input volts, and it's set for a bulb with such a module, it would be able to power an incandescent bulb.

Re: There's something off about LED bulbs

#807

Post by TexanFeller »

DougN7 wrote: post #135
amluto wrote: post #74

Earlier quoted context omitted.

> The same light quality is vastly more expensive to achieve with LEDs, even if you account for high electricity prices. In a screw base, maybe. But compare: https://www.digikey.com/en/products/detail/luminus-devices-i... $25 for an excellent 700mA driver, 86% efficient. https://www.digikey.com/en/products/detail/bridgelux/BXRH-30... $3.45 for a very nice, ~2000lm 97 CRI LED, about 99 lm/W. (Efficiency goes up quite…

This is just an anecdote, but I’ve had multiple “10 year” LED bulbs fail after just a year or two. I suspect much of the claims for these bulbs are theoretical as they just don’t hold up, probably for reasons the grandparent poster is pointing out.

All the big name brand(Cree etc.) bulbs I've bought have been going strong for 5-12 years. Out of dozens the only ones I've ever had fail were off brand or special purpose like LIFX wifi bulbs.

Re: There's something off about LED bulbs

#808

Post by walterbell »

leobg wrote: post #744
walterbell wrote: post #737

Earlier quoted context omitted.

Could we improve discovery of these indie sites via HN or elsewhere? A standard tag for Algolia/web search could work, if any spam comments with the same tag were flagged.

That would be the benevolent Engelbart version of AI, wouldn’t it? Instead of dumb capitalism, clickbait and silly content marketing driving human activity, to have an AI that saves us from wasting our time figuring out the answer to questions that have been answered long before. And then, instead, points us to those questions that have not yet been asked, much less answered. What experiments have not yet been done.…

There have been attempts to reboot webrings for indie site discovery. With AI harvesting and monetizing indie sites, there is some risk of future content being gated by pay/auth/bot walls. Another approach could be private overlay P2P VPNs where participants are invited/vetted by the social contract of a small community.

(random indie site: wet/dry shop vacuums, https://news.ycombinator.com/item?id=32411206)

Re: There's something off about LED bulbs

#809

Post by charrondev »

bobbylarrybobby wrote: post #253
DennisP wrote: post #119

Earlier quoted context omitted.

Sunlight is great during the day but in the evening, you want to be closer to the color of sunsets and campfires.

For this reason I think it's great to connect different temperature bulbs to each light switch in your house and switch between them during the day. I keep all of my bulbs on during the daytime and then switch to just the warm ones at night.

I have hue builds in my house and have them programmed to warm their color temperature as the day progresses into the evening, and dim themselves down significantly as it gets later.

Re: There's something off about LED bulbs

#810

Post by ccooffee »

wrycoder wrote: post #653
aimor wrote: post #633

Some people seem to have different memories than I do of what it was like buying lightbulbs before LEDs came out. I remember incandescents also having a variety of color quality, lifespan, and decorative options. I remember having the choice between bargain bin bulbs and luxurious options, making sure to outfit a room with a single brand so everything looked the same, realizing it's more difficult to read with this o…

And yet I have a growlight that specs its output in moles of photons per second.

I had been unaware of measurement according to "moles of photons", though I suppose it's not surprising. I've never really understood what a mole is other than "we decided to pick this number as a constant multiplier when doing small calculations".

Per wikipedia[0], there's a vaguely defined unit, the Einstein, which may be defined as the energy in a mole of photons. (The vague definition being because each photon may have different amounts of energy, and thus an Einstein would be some weird function in order to describe total energy.) Wikipedia suggests using measures of Photosynthetically Active Radiation (PAR)[1], like Photosynthetic photon flux (PPF) instead. I suppose this is because PAR is literally defined to measure according to "what plants crave", but it also allows bounding the "total joules of energy" above and below by the PAR wavelength limits.

[0] https://en.wikipedia.org/wiki/Einstein_(unit)

[1] https://en.wikipedia.org/wiki/Photosynthetically_active_radi...

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