New development could lead to more effective incandescent lightbulbs | Hacker News Reader

New development could lead to more effective incandescent lightbulbs

bbc.co.uk

27 pointsagd25 comments

As a side not, something that never happened to me with incandescents happened with halogens. I refuse to buy anything with the mercury warning and noticed the halogen the was shaped like an incandescent in the 60 W replacement size. I bought it and had it in for about a week. One night I hear a "boom" that wakes me up. It sounded like a muffled shotgun. I walked into the living room to discover[1] the halogen had blown up scattering little glass shards all over the living room. I was not happy.

I went out and bought a cheap LED from Walmart[2] which seems pretty good and turns on right away. I do wonder who is the actual supplier. No heat, bright, and hasn't blown up.

We still have a couple of packs of incandescents at work because we use the chicken coop method of heating a box outside during the winter.

1) well my foot discovered this which required first aid

2) http://www.walmart.com/ip/Great-Value-GVRLA6027ND-Great-Valu...

I've had two Cree brand LED bulbs melt apart and blow fire. I was glad to be around so I could get them shut down. And a little terrier afterwords of what could have happened. I've had at least three Walmart brand LED bulbs that have lasted less than a couple months. (No fires though!)

Surely I'm not the only one seeing this kind of failure rate?

I'm making a personal collection of the failed LED bulbs for future purchasing decision....

It sounds like you have more serious problems here, better check your electric installation. I have cheap Chinese LED bulbs from eBay and even they shine happily after >2 years now.

Yeah, I have probably have 25 LED bulbs in the house. I've so far only had troubles with two brands

Out of curiosity though, what kind of electrical problem would disproportionately affect LEDs?

LED bulbs have drivers (usually AC to constant current converter) integrated so they should stabilize power themselves. My guess would be that there might be high voltage spikes that managed to burn a driver. Another possibility, that just came to my mind -- LED's, especially high power ones like Creed, become very hot, maybe your bulb slot is very tight and isolated and there's not enough room to dissipate the excess heat?

The LEDs are working great, the halogen went explody. I have no problems with the LED.

My answer was dedicated to danielvf's comment.

It's worth mentioning that Cree are the company that make the actual LED, and they are used in a huge spectrum of low to high quality products. Cheap Chinese manufacturers often buy these LEDs, and put them behind really cheap electronics, then sell them with a generic name including "Cree" in the brand (or -fire, for flashlights). The lumen output can also be widely inaccurate.

So if you do end up buying more online, you should be wary.

These were actual Cree brand bulbs, in Cree boxes, bought from a big box store, and I talked to Cree customer support after the problem. They sent me replacements but in fear I've never installed the replacements.

> something that never happened to me with incandescents happened with halogens ... the halogen had blown up scattering little glass shards all over the living room

I've had one incadescent explode. Maybe it didn't scatter glass all over the room, but the bulb was definitely blown and lied in pieces on the floor.

The halogen had an inner and outer bulb, it went everywhere.

More details here:

http://www.purdue.edu/newsroom/releases/2016/Q1/innovation-c...

This is very good; many people will like the angle that they are even using recycled light now, never mind paper, metal, textile or plastic. :)

I think we're a little too late -- like that guy who invented a better dodo trap or the lady who came up with a more effective polio vaccine.

Not necessarily. There could still be room for these bulbs if they turn out to be as energy efficient as LEDs or CFLs, but are less expensive to manufacture (leading to lower off-the-shelf costs).

Don't hold your breath. The antireflection coatings and photonic crystals required to reach LED efficiencies would be much more complex (expensive) than the LEDs themselves.

This is just grant fishing. It's not going anywhere. Similar technologies are potentially more useful for thermophotovoltaics, but even there they aren't cost effective.

Incandescent lightbulbs often are suitable for small form factors unlike spiral incandescents, and don't suffer from the heat dissipation issues which LED lights do. A more efficient version of the technology would be advantageous in areas where those two things are important.

Can you elaborate on the heat dissipation issues?

You have to keep the LEDs relatively cool or their lifetime decreases substantially. That's why most LED bulbs of reasonable intensity have a heat sink integrated into their design. In practice, this isn't too much of a problem when you're designing the entire bulb (and perhaps the housing). But it does mean you're still stuck using incandescents as, e.g., oven light bulbs.

(I say "stuck" mostly in a design sense - the inefficiency is irrelevant in that application. But LEDs give more shape flexibility. I'm a fan of how they've been deployed in refrigerators to provide more uniform illumination, for example.)

There's another aspect to this development. One benefit of incandescent lamps vs. CFL or LED is superior CRI (color rendering index).

CFL/LED lamps produce output having a discontinuous spectrum, fluorescents with prominent green and LEDs blue emission. Consequently these light sources can be much less desirable where accurate color rendering is important, for example critical color matching, art galleries/museums, etc.

I've found it difficult to replace continuous spectrum sources with LED lights in particular. The latter are much more energy efficient and have greater useful life span, but unsuited to photography, etc., where quality of color rendering is crucial.

Quite likely there's a large enough market for improved incandescent lamps to warrant further development.

Agreed, and thanks for bringing this up. This is why Tungsten and HMI lighting is still a thing. Remote phosphor lights from Cineo are supposed to address this, however. But this would not be used in a residential setting, more for commercial lighting situations.

How does remote phosphor help with color rendition? After all, white LEDs also use blue light + phosphor, so how do the remoteness help?

Indeed, the Cineo lights claim high CRI values. Per their website, the lights are intended for cinematography and similar applications. I surmise they wouldn't be used in homes or commercial spaces, at least that would be rare. The lighting systems are quite expensive, especially the bigger units.

Not yet seen CRI info for more ordinary incandescent replacement lamps, but potentially they could begin to approximate the traditional light emitters especially at lower color temps, <3000K.

Just about every interior design showroom or expo has "Edison bulbs" (fancy incandescents) for their aesthetic appeal.

They also have a better color light for, you know, seeing things. LEDs vary and can get pretty close.

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