Electroluminescence as a phenomenon was discovered in 1907 by the English experimenter H. J. Round of Marconi Labs, using a crystal of silicon carbide and a cat's-whisker detector. Russian inventor Oleg Losev reported creation of the first LED in 1927. His research was distributed in Soviet, German and British scientific journals, but no practical use was made of the discovery for several decades, in part due to the very inefficient light-producing properties of silicon carbide, the semiconductor Losev used
i'm pretty sure 170lm/w will be achieved by leds soon, if not already,The highest perception of brightness experienced by the human eye is generated with green light on the 555 nm wavelength. The greatest luminous efficacy which can theoretically be achieved at 555 nm is, altogether, 683 lm/W.
Well it turns out, 210lm/w leds already exist, and are sold in pretty much any hardware store. lolNot likely. LED are already bumping up against theoretical efficiency limits. There's literally no room for improvement. Afa LED "constantly improving," that improvement is towards being more like incan, not with efficiency improvements, and the more like incan they are, the less efficient they are.
This isn't is a football game. LED is not your team. It shouldn't matter to you whatsoever what your light source is, so long as it is efficient and is not hurting you. LED has fallen flat on a lot of promises, but it's just as much greed as it is anything that is the problem with them. Cheap crap is cheap crap, and that is mostly the problem. But even the best LED light sources have a spectrum curve that is unnatural. If that is fixed, incan may be dead, but I haven't heard of anyone working on that, just on perceived tint, color temperature and high CRI hiding an unnatural color spectrum still weighted in the blue end. That's, so far, very bad. Again, maybe they'll fix it. Maybe they won't and incan will return in high efficiency form. We'll see.
And I don't think steam powered cars were ever really anything. Horse and buggy, otoh, never really completely went away.
This post is mostly about your subjective preference for incandescent lighting, as opposed to any objective advantage. Consider that I personally found incandescent light so lacking that I preferred to do my homework under one of those really lousy halophosphor fluorescents we had in the kitchen in the 1970s. Yes, it didn't render some colors well at all, but at least white looked closer to the type of white I saw under sunlight, not the awful yellow it appeared under incandescents. I don't care if something has a 100 CRI when the color temperature is so way off that there isn't even a white point, just shades of yellow.I'm pretty certain that if there was an incan tech 100x more efficient than the most efficient LED, you guys would still choose to slowly blind yourselves.
If LED didn't suck, I probably would, too, but thus far, I haven't seen or even heard of any LED lighting, let alone an LED flashlight, that had a decent constant current driver with an emitter with tint and temperature worth the materials used to construct it. Sure, they're really really neat, and in small doses they get the job done, but except for the increase in efficiency, the cheapest, crummiest incan is head and shoulders above the most expensive LED, as far as the quality of the light is concerned.
And this only matters because that is what it is... a light. Right? I'd feel the same way about a car that was ten times more efficient but had a terrible ride, because that is the whole point, the ride, getting somewhere. I'd feel the same way about a really ultra-efficient printer that couldn't print worth a dang.
I'd like to see LED get better, but I'm not deluding myself about the current state of commercially available LED, which no matter how much we like them and prefer them to incan and even hate incan, LED is slowly blinding us and insidiously shortening our lives. That I can not get over as easy as others.
So I'll use more batteries, pay for more electricity, but at least I'll have superior light that is neither permanently blinding me nor cutting my life short.
But there is an objective advantage with incan in the quality of the light itself, and in neither slowly permanently blinding due to a color spectrum with too much blue, nor shortening lives by disrupting circadian rhythms, of which studies have appeared that show that is the case with LED.This post is mostly about your subjective preference for incandescent lighting, as opposed to any objective advantage.
but at least white looked closer to the type of white I saw under sunlight, not the awful yellow it appeared under incandescents
LED isn't blinding us any more than any other light source.
Your blind spot is not seeing that some people actually prefer the light LEDs emit over incandescents. I wouldn't use incandescent if it was 100 times more efficient than LED for that reason alone. I can't see well under the type of light it emits, plus I get a headache being under it for too long.
I'm pretty certain that if there was an incan tech 100x more efficient than the most efficient LED, you guys would still choose to slowly blind yourselves.
The problem is that incandescent has too much red in it. Ideally, a light which can mimic sunlight exactly would be the ideal light source. As I mentioned in other threads, LED can actually come very close to that. The blue spike is more like a tiny blue hump with such LEDs. Not perfect, but still far better than any other manmade light source.But there is an objective advantage with incan in the quality of the light itself, and in neither slowly permanently blinding due to a color spectrum with too much blue, nor shortening lives by disrupting circadian rhythms, of which studies have appeared that show that is the case with LED.
There are limits to that which vary by person. For me the lower limit is around 3500K. Anything lower and I can sit under it for hours but it'll still look yellow.Maybe initially, but the human brain will adjust the white balance pretty rapidly so that what you initially perceive as yellow will look white.
Yes, but as mentioned the higher the CRI, the smaller the blue spike. I hope you know sunlight has a copious amount of UV in it. LEDs have none. UV is far more damaging than blue light.There is more blue light in LED than other light sources, regardless of the color temperature of the LED or what its CRI is, its color spectrum will show it has a blue spike, unlike, say, sunlight, which has blue in it, but the majority of the light from the sun is not blue light, as is the case with LED. Studies suggest that continued exposure to blue light over time could lead to damaged retinal cells. This can cause vision problems like age-related macular degeneration.
Again, that's primarily due to screens on the devices we insist on using, not due to general lighting which is far lower in intensity. Common sense dictates not to stare at a screen before you go to bed.But the disruption to circadian rhythms is likely more serious, as it has been correlated with diabetes and heart disease. Incan doesn't do that.
PWM isn't inherent to LEDs. I personally avoid it when I design stuff, preferring instead to simply reduce drive current. Having grown up in the era of fluorescents which flicker at 120 Hz, I'm not keen on intentionally introducing any flicker into light sources, even if it's at a frequency supposedly too high for us to detect.And I have never had worse migraines than after sitting in undetectable PWM for 30 minutes.