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There's something off about LED bulbs

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Re: There's something off about LED bulbs

#911

Post by simplotek »

midoridensha wrote: post #904
xpe wrote: post #864

Earlier quoted context omitted.

Until I see someone defining a representative example and running the numbers, I'm skeptical of their DC vs AC commentary. I say this, because I was guilty of this exact shortcut thinking (in another comment). But I paused and thought to myself "I should run the numbers before just repeating the usual voltage drop criticism". So I compared scenarios and it depends a lot on the topology, lengths, costs, and situation…

>Sure, a whole house system doesn't typically make sense, but I don't think that's what people are really talking about. I think people are interested in hybrid systems; e.g. DC power supply for each room. I completely disagree. Where exactly are you going to put a power supply in a room? Make a special electrical box for it? Won't it be unsightly in many rooms, or need some huge special panel that looks like a break…

> I completely disagree. Where exactly are you going to put a power supply in a room? Make a special electrical box for it? Won't it be unsightly in many rooms, or need some huge special panel that looks like a breaker panel?

This sounds like a non-issue, specially considering the pervasive use of "unsightly" installations like air ducts, heating vents, radiators, electrical sockets, telecommunication service panels, routers, and even light fixtures.

If you intentionally dismiss obvious solutions, of course you only end up with problems without obvious solutions.

> It's supposed to be dismissive, because this whole discussion is (...)

If you have nothing to add, please add nothing.

Re: There's something off about LED bulbs

#912

Post by yourusername »

kalleboo wrote: post #892
Zak wrote: post #533

Earlier quoted context omitted.

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…

One of the problems is that in some countries like the US, ceiling lamps are hard-wired and not "user-replaceable", so people have to resort to using those stupid bulbs in their old fixtures. I live in Japan, and instead of just a pair of wires coming out of the ceiling, there is a standardized "ceiling socket" [0] which can also support the weight of a lamp. This means that swapping out light fixtures is plug and pl…

In the Netherlands we have just a pair of wires coming out of the ceiling but everyone replaces their own lamp fixtures anyway. Most people should be able to manage clamping or screwing down the brown or black wire to the L and the blue wire to N.

Re: There's something off about LED bulbs

#913

Post by IshKebab »

cal85 wrote: post #367
simongray wrote: post #258

This article and comment section is bizarre to me. It's like travelling back in time to the 2000s. We've only used LEDs in my country for, what, 15 years now? They are perfectly fine, no issues really, much cheaper than incandescent bulbs of course. We just buy the ones in IKEA and they haven't really failed us so far.

I guess you can't tell the difference? For me it's huge. I recently changed my bathroom downlights from dimmable LEDs to dimmable halogens, and it's so much nicer. The colour temperature was the same, so I guess it's not that. It's something else about the way they work. I don't profess to know why, but I can absolutely tell the difference, and I have a very clear preference now. And this is after a decade of me bein…

You're right that the colour temperature isn't the whole story - it's a single number trying to represent a spectrum which is a line graph. So you can have wildly different spectra with the same CRI.

But even so, good LEDs are perfectly fine. Don't assume that all LEDs are crap because you bought one cheap set and they weren't very good.

Re: There's something off about LED bulbs

#914

Post by thrashh »

Dylan16807 wrote: post #901
thrashh wrote: post #865

Earlier quoted context omitted.

It’s only a few $ more. And it says on the box. I usually stick to the same brand too. All Phillips bulbs are 90+ CRI and some are 95+ so I just buy Phillips. Problem solved.

"A few dollars" is a bad way to describe the difference between $2 and $25.

I consider $3.75 for a Phillips 95+ CRI bulb a few dollars more.

A Home Depot bulb is like $2.75.

I hate that you have to research bulbs but you’re making it out way harder than it is.

Re: There's something off about LED bulbs

#915

Post by cal85 »

IshKebab wrote: post #913
cal85 wrote: post #367

Earlier quoted context omitted.

I guess you can't tell the difference? For me it's huge. I recently changed my bathroom downlights from dimmable LEDs to dimmable halogens, and it's so much nicer. The colour temperature was the same, so I guess it's not that. It's something else about the way they work. I don't profess to know why, but I can absolutely tell the difference, and I have a very clear preference now. And this is after a decade of me bein…

You're right that the colour temperature isn't the whole story - it's a single number trying to represent a spectrum which is a line graph. So you can have wildly different spectra with the same CRI. But even so, good LEDs are perfectly fine. Don't assume that all LEDs are crap because you bought one cheap set and they weren't very good.

I have bought almost exclusively LED bulbs over the last 10-15 years. As a nerd, I always look fairly carefully at the specs, and I choose good ones. If, when I buy off-brand halogens one time without really looking into the technical details and it's like "Oh yeah, this is how artificial light is supposed to look", then that's a problem with LEDs, not with me not looking hard enough for good ones, because I look much harder than a typical consumer would.

Re: There's something off about LED bulbs

#916

Post by Gordonjcp »

If your power is coming from renewables anyway, you're probably far more eco-friendly using incandescent bulbs.

Someone tell me why I'm wrong, but I feel like a coil of wire in a milk bottle with all the air sucked out that you could make in a blacksmith's forge is going to be cleaner overall than 100g of plastic, fibreglass, epoxy, copper, gallium arsenide, phosphor, and a billion-dollar factory to build it in.

Re: There's something off about LED bulbs

#917

Post by code_biologist »

vl wrote: post #611
jghn wrote: post #526

Earlier quoted context omitted.

Yes, but this is exactly what I'm asking. How do I find the ones designed in a buy it for life way? Or at least ones designed to last longer than the crap on the Home Depot shelves.

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")…

Just another thumbs up for 1000bulbs. I've made a small order through there, but I like my bulbs. It seems to get very expensive quickly going beyond 93 CRI.

Re: There's something off about LED bulbs

#918

Post by formerly_proven »

Majromax wrote: post #407
sparker72678 wrote: post #223

Earlier quoted context omitted.

Agreed the e-waste issues are real, but how did you get incandescents to last 10 years? I replaced every dang one after 12 months or less, every time.

> how did you get incandescents to last 10 years? As a general answer, dimming. Incandescent bulbs are fantastically sensitive to applied voltage; Wikipedia's article on the subject ( https://en.wikipedia.org/wiki/Lamp_rerating ) notes that bulb lifespan is inversely proportional to the applied voltage to the fourteenth power or so. In an ordinary home you can't directly reduce the supply voltage, but dimming a highe…

That page is also why the popular depiction of the Phoebus cartel (as in: they intentionally made 1000h bulbs, but could have made 3000h bulbs instead that were otherwise identical, like e.g. Veritasiums popular video) is wrong. For classic incandescent bulbs, color temperature and lifetime limit each other. It is not possible to make a 2500K incandescent bulb that lasts longer than about 1000 hours, and a 3000 hour bulb will always have a dim and warm output. Because that's how it gets to 3000 hours.

Re: There's something off about LED bulbs

#919

Post by tremon »

xpe wrote: post #864
midoridensha wrote: post #857

Earlier quoted context omitted.

It's because of Ohm's Law. Any sophomore-level electrical engineering student could answer this question immediately.

Until I see someone defining a representative example and running the numbers, I'm skeptical of their DC vs AC commentary. I say this, because I was guilty of this exact shortcut thinking (in another comment). But I paused and thought to myself "I should run the numbers before just repeating the usual voltage drop criticism". So I compared scenarios and it depends a lot on the topology, lengths, costs, and situation…

I'm skeptical of their DC vs AC commentary

It's not about DC vs AC, it's high-voltage vs low-voltage. The power dissipation by wire resistance scales with the square of the current ($P=RI^2$), and low line voltage means that you need large currents to transmit the same amount of power.

Re: There's something off about LED bulbs

#920

Post by tremon »

midoridensha wrote: post #904
xpe wrote: post #864

Earlier quoted context omitted.

Until I see someone defining a representative example and running the numbers, I'm skeptical of their DC vs AC commentary. I say this, because I was guilty of this exact shortcut thinking (in another comment). But I paused and thought to myself "I should run the numbers before just repeating the usual voltage drop criticism". So I compared scenarios and it depends a lot on the topology, lengths, costs, and situation…

>Sure, a whole house system doesn't typically make sense, but I don't think that's what people are really talking about. I think people are interested in hybrid systems; e.g. DC power supply for each room. I completely disagree. Where exactly are you going to put a power supply in a room? Make a special electrical box for it? Won't it be unsightly in many rooms, or need some huge special panel that looks like a break…

Where exactly are you going to put a power supply in a room? Make a special electrical box for it?

Switched-mode power supplies can be as small as your average Arduino board. They can fit inside the space used for wall outlets or light fixtures. Or you can put the DC transformer inside the light switch.

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