There's something off about LED bulbs • Hacker News Board

Re: There's something off about LED bulbs

#641

Post by stevenkkim » Thu, Mar 30, 2023, 6:26 PM UTC

SamBam wrote: post #250

stevenkkim wrote: post #205

I came across this article on HN recently: https://www.sevarg.net/2023/02/11/how-your-leds-are-killing-... https://news.ycombinator.com/item?id=34902429 After reading it, I realized that having overhead led lights in our home were possibly contributing to my worsening sleep and general tiredness over the past few years. Granted, we used 4100k lights which are much bluer than 2700k. We swapped all our leds back to inc…

> Granted, we used 4100k lights which are much bluer than 2700k. You had this realization and yet still went the route of switching back to all incandescents? It's trivially-easy to find 2700K LED bulbs. The ones I have look just as good as the old incandescent. And despite the article making it sound like you need a PhD to sort it out, you don't: most medium-end 60W-equivalent, 2700K LED bulbs look good and are easi…

The article says that even 2700k leds have a blue light spike (albeit smaller than the 4100ks) since the led source is blue light.

Also, maybe it just in my head, but I think the light from incandescents/halogens look nicer than leds... it feels more natural.

Re: There's something off about LED bulbs

#642

Post by smolder » Thu, Mar 30, 2023, 6:26 PM UTC

jsmith45 wrote: post #516

PragmaticPulp wrote: post #228

Earlier quoted context omitted.

You can go buy high CRI, high quality bulbs right now. Nothing is stopping you. Here is one common vendor: https://store.waveformlighting.com/collections/a19-bulbs/ The issue isn’t that MBAs have cost reduced bulbs for no reason. The issue is that 95% of consumers will only choose the cheap bulbs, period. As a result, that’s what gets produced at scale. > We know how to mass-produce quality LEDs to the point entire T…

I really wish i could find a brand that would reliably tick all the boxes: - Does not overdrive the LEDs and Does not run power supply components at the limit of what they can. (Thus good longevity) - Has a current based driver, so that slight voltage shifts from an appliance kicking on don't result in an obvious brightness shift. - Suitable for use in recessed lighting or enclosed fixtures. (For better or worse, can…

The only bulbs I've found that work in tight enclosures without overheating and failing are a design that's probably 90% aluminum heatsink by weight and over 50% by volume, with a relatively small dome diffuser on top. I couldn't find a US distributor, so bought a box direct from the manufacturer on Alibaba. They were $20+ per bulb even from the factory, so not cheap. Beyond the crazy cooling, they have a thermal shutoff feature to prevent failure if they get too hot. Generally it's better to find an appropriately breathable fixture for LED bulbs, or even better, ditch retrofit bulbs and get something with a separate DC power supply.

Re: There's something off about LED bulbs

#643

Post by samtho » Thu, Mar 30, 2023, 6:27 PM UTC

int0x2e wrote: post #440

samtho wrote: post #379

Earlier quoted context omitted.

I am designing an off-grid cabin with a solar panel array charging a bank of batteries with a propane generator backup. I run ethernet as power with a custom designed PCB that terminates at the outlet side where it exposes a 20 watt USB charging port and an ethernet port. The lights are all basically cut 12v light strips inside of old light fixtures with a custom controller that also terminates PoE. The 48 volts that…

If you're willing to share your design, I'm sure there are other folks like myself who think this is a cool idea. I've wanted to do PoE (or passive PoE) for lights for a while now...

I am going to open source it. The goal was to be able to get all the SMD stuff available at JLPCB so you can just send it to be fabbed (with some thru-hole components you would just solder yourself) or I would also sell them at cost + 10%. My brother designed some 802.3at chips and was going to have him review my work first as I don't want to send out into the world a poorly design power system (there are enough of those things out there unfortunately).

Re: There's something off about LED bulbs

#644

Post by tomtheelder » Thu, Mar 30, 2023, 6:28 PM UTC

shanecleveland wrote: post #432

I replace the standard size LED bulbs more than any other bulb. Of all new bulbs in a new construction home from 2016, I do not have any original standard size LED bulbs (mix of open, enclosed and outdoor applications). I still have original incandescent bulbs, fluorescents and in-ceiling LED can bulbs in place. I'm not sure what makes the flood-style LED can bulbs so much better. I have not replaced a single one ind…

I put LEDs in about 10 years ago and have never replaced one. I used to have a big drawer full of incandescent ones because they would fail pretty regularly

I think there just might be more of a spectrum with LED bulbs, since they are more complicated than incandescent ones. The worst ones are much worse, but the best ones are far better.

Re: There's something off about LED bulbs

#645

Post by neuronexmachina » Thu, Mar 30, 2023, 6:30 PM UTC

Tarball10 wrote: post #528

jghn wrote: post #278

Earlier quoted context omitted.

The big problem for me is, as a consumer, how do I know that brand X is producing quality bulbs that'll last a long time? I'm very happy to pay more for that. How does one sift through marketing to get to actual quality? And then how do I know that they stick with the high quality approach? What happens when a brand decides to rest on the laurels of their brand name and start slipping in lower quality parts?

California's JA8 certification requires LED bulbs to meet specific criteria related to efficiency, lifespan, and light quality. - Efficiency >= 45 lumens per watt - CRI >= 90 - R9 Color Rendering value >= 50 - Rated life >= 15000 hours - Minimum dimming level - Flicker Theoretically if a bulb is listed as JA8 compliant (and the certification isn't fake) you know it at least meets these thresholds.

> CRI >= 90

This one was a little tricky for me when I was buying bulbs last year. I prefer warm-colored bulbs, and I was kind of confused why Amazon kept on saying it was refusing to ship bulbs to me. It took me a while before I realized it was because I'm in CA and the CRI was too low, and Amazon didn't have a way to just filter by CRI. Eventually my wife just ended up finding some warm-ish LED bulbs at a local store.

Re: There's something off about LED bulbs

#646

Post by twoodfin » Thu, Mar 30, 2023, 6:30 PM UTC

The hidden, diffuse social & economic cost of forgoing a carbon tax.

Re: There's something off about LED bulbs

#647

Post by malfist » Thu, Mar 30, 2023, 6:32 PM UTC

last_responder wrote: post #264

throwthrowuknow wrote: post #64

Earlier quoted context omitted.

[flagged]

Green account . A mod? Admin? Either way reported.

Green accounts mean it's new, if you couldn't tell by their trollish post.

Re: There's something off about LED bulbs

#648

Post by pwg » Thu, Mar 30, 2023, 6:35 PM UTC

zaroth wrote: post #358

bryanlarsen wrote: post #287

Earlier quoted context omitted.

We've had 2 standard DC outlets for a while now: 12V cigarette lighter and 5V USB. You do often see them in odd places. But the voltage and wattage of those specs is too low to be useful, so they haven't evolved into DC power distribution. USB-C PD is at a useful voltage & wattage level, and so is Ethernet POE. I wouldn't be surprised to see them start to be used for general power distribution in niche applications,…

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 illuminate either).

Screwing in an LED bulb with integrated power supply, the external supply will still feed the constant current value, so what happens depends upon the design of the LED bulb's integrated power supply. If 25mA is enough to drive everything, the LED bulb might light up. If 25mA is not enough to drive everything, most likely nothing lights up.

Re: There's something off about LED bulbs

#649

Post by notatoad » Thu, Mar 30, 2023, 6:35 PM UTC

_rs wrote: post #492

notatoad wrote: post #413

Earlier quoted context omitted.

just because somebody decides to geek out about LED bulbs, does't mean all those stats that are theoretically measurable actually make a difference. the 4-for-$10 A19 LED bulbs from amazon or ikea are flicker free to my eyes. i've bought some fancy bulbs with big metal heatsink bases, supposed "high CRI" ratings, equivalently high price tags. to my eyes, i can't see the difference. the super-cheap bulbs from one of t…

> are flicker free to my eyes Very rarely will bulbs visibly flicker in my experience. What happens instead is after several hours I'll start to get headaches and feel fatigue without knowing exactly where it's coming from. Since I replaced my Hue bulbs (which flicker, and I proved it by just using my smartphone camera even) I've felt so much better at home

>which flicker, and I proved it by just using my smartphone camera even

all bulbs have some flicker, and the fact that it resonates with your phone screen's refresh rate or your camera sensor's sample rate doesn't really mean anything.

Re: There's something off about LED bulbs

#650

Post by elihu » Thu, Mar 30, 2023, 6:38 PM UTC

It's perhaps worth mentioning that metal halide bulbs are an alternative to LEDs that are efficient and produce high quality light. They use an electric arc in an inert gas between tungsten electrodes. The old high pressure sodium lights used in street lights and gymnasiums are basically the same technology, but by using a different gas mixture you get a more normal color temperature.

They aren't generally used in residential buildings. You could install them, but it tends to be kind of expensive and complicated because they require a ballast. Also, they tend to be most efficient at high wattages, and most people don't want their house lit like the surface of the sun.