The Dark Side of LED Lighting

the great thing about led's is u can tune them to put out practically any spectrum of light u want. most dont go into the deep blues or reds unless you regularly find yourself inside grow houses with artificial lighting

This is the same Dr Mercola that said mattress springs cause cancer. He is well known for his outrageous claims.

Anyway, warm leds don’t emit much blue like he says they do, and generally less than fluorescent.

The 'soft white' or 'warm white' version of LEDs (along with 'sunlight' which is now blue-white not bright yellow-white like it used to be) is so much duller and the bulbs heat up so fast, faster than CF bulbs in my experience!

A contractor friend who is installing FEMA communications at PD & FDs slipped up one evening and started talking about how the LED lights being installed all over public spaces like parks, freeways, etc are actually hidden surveillance equipment which transmit video and audio over the new 5G networks they are installing everywhere, too.

I keep a hoard of incandescent light bulbs in my basement just in case. I hate any other kind. I'd sooner go back to candles or kerosene lamps than use those things. Never liked LED. Tube lights make me feel spacey. And CFLs give me migraines.

originally posted by: TheRedneck

But the biggest poppycockness is the assertion that LEDs somehow create too much blue. All white LEDs contain red, green, and blue LEDs internally; otherwise the light would not be white. If the light produced is close to the light produced by an incandescent bulb, judged by no noticeable difference in lighting quality, then there is no excessive amount of blue light.

TheRedneck

Doing a lazarus thing on an old thread I know but just to clear things up a little:
Not all white LEDs contain R,G&B LEDs, only the variable colour types are made this way which makes them more of a technical challenge to balance the outputs as each LED has a different forward bias characteristic = more expensive to use.
There are also the addressable type RGB chips but these are for novelty applications, not general lighting. The vast majority of white LED lamps are based on high output LEDs in the Blue to UV end of the spectrum with a phosphor coating which fluoresces at the desired colour temperature the same way a white mercury vapour type fluorescent tube works.

The LED encapsulation should restrict any concerning levels of Blue-UV escaping but that comes down to quality of manufacturing. This type of LED can be identified by shining a UV light into the LED - the phosphor coating will glow in the yellow to greenish range. Single colour LEDs do not fluoresce.

a reply to: Realtruth

I am going to tell a story for which I have absolutely no proof beyond my word. Here it is.

Our house has been converted to LED bulbs.

In February, I bought a FitBit Alta HR, which is a wearable device that tracks steps, calories burned, sleep, and heart rate. (I know, I know...)

In May, I read an article that suggested LED lighting may be harmful to eyes.

That same week, I found 4 60w incandescent bulbs at Autozone, and I replaced the 4 LED bulbs in my office ceiling fan. I work from home.

By the next week, my average heart rate had declined 3 beats per minute, from 72 to 69.

It is now July, and my heart rate is still lower than it was February - mid May.

The only difference is the bulbs.

Take this how you will, it is the truth.

a reply to: Pilgrum

It is not possible for a discrete LED to produce white light. White light is a mixture of all visible colors. The very nature of how LEDs function means they deliver one specific frequency (within a tiny tolerance range) of light. That frequency is based on the energy levels as free electrons and holes combine in the PN junction. Different materials have different energy levels and produce different frequencies of light. That's why laser LEDs were so easy to develop; the only difference is that a normal LED's light is not in phase, but has a random phase. the principle behind the light production is the same.

I am quite familiar with RGB LEDs. they are used to produce varying colors like you said, and are thus three distinct LEDs which are independently addressable. White LEDs are similar, but not independently addressable; all three LEDs are on the same silicon chip, and may actually be integrated with each other to some extent. Color balance is obtained by the various built-in chip resistances and size of the junctions.The covers may be diffused or designed to block UV light, but they are not phosphorescent; you're thinking of CFLs. One of the LED bulbs here doesn't even have a globe over it anymore; one can see the individual LEDs. The color is essentially the same as those with a globe, but the light is slightly "harsher" since the globe was diffused.

I have a roll of 1000 super-bright T-1 3/4 white LEDs in my shop I bought surplus some time back. They are crystal clear when off. I have another roll of 1000 super-bright T-1 3/4 red LEDs someone brought and dropped off. They are crystal clear as well. I cannot look at them and tell the difference; I have to do a test to make sure which roll I have (just quickly tap one against a 5V supply).

TheRedneck

a reply to: TheRedneck

I have many rolls of SMD LEDs here too - I can pick the white ones by shining a UV flashlight into them to see the phosphor layer which can be very small in encapsulated 3mm & 5mm non-SMD types. Larger high power devices such as floodlights etc are easier as you can see the yellow looking phosphor in those which is usually rectangular. I can also see subtle differences in the phosphor colour under UV which was important when making LED backlight conversion for CFL backlit monitors.

The key to making blue and UV LEDs was gallium nitride which won a nobel prize for physics for the scientists who created the technology in 2014 Shuji Nakamura

I'm not disputing the existence of RGB leds (got rolls of them here), just saying that typical white leds (now) are not RGB but GaN UV LED with a phosphor layer creating the white light so effectively solid state fluorescent lamps. The phosphor determines the colour temp of the white light (EG cool white, warm white, daylight etc).

No big deal as long as you can see what you're doing at night

5050 UV - 3 leds (actual leds are less than 0.3mm)


5050 White - same setup with 3 UV leds except for yellow phosphor window


5050 RGB

originally posted by: tulsi
A contractor friend who is installing FEMA communications at PD & FDs slipped up one evening and started talking about how the LED lights being installed all over public spaces like parks, freeways, etc are actually hidden surveillance equipment which transmit video and audio over the new 5G networks they are installing everywhere, too.

As someone in the industry I can tell you that almost no municipality can afford anything more than your standard area lighting. There are IOT area lights being developed that can do this but no one wants them at this point.

a reply to: Pilgrum

Gallium nitride was the breakthrough that led to blue LEDs (hence the different driving voltage), and in turn blue LED light was the breakthrough that led to the possibility of white LEDs. Again, white is not a frequency. Blue is, green is, and red is. Yellow (amber) is a combination of red and green light and those have been around almost as long as red and green.

The RGB LEDs are easier to see the individual components in because each component has to be capable of individual access. White (and amber) LEDs do not need this individual access and can be encapsulated on a single chip. It is not possible to see the individual components in a white or amber LED, because the components are on the molecular level... but they are there, nonetheless.

Just like you cannot see the individual transistors in a computer chip. They're there, millions of them, all too tiny to be seen by the human eye.

One problem comes along with using individual elements to create white light: two elements cannot occupy the exact same space at the exact same time. So the red, green, and blue light components do not originate from the exact same position and can give colored shadows. Early versions of white LEDs had this issue. Advances in miniaturization has led to them being encapsulated on the same chip, which reduces this colored shadowing effect to the point it is un-noticeable, but this also means the individual elements cannot be directly accessed. That's why you can see the components in an RGB LED while you cannot always see them in a white LED.

In addition, the diffusion coating shown in the pic further diffuses the light colors together. The result is what appears to be pure white light with no discernible color shadows.

Different color temperatures are achieved by adjusting the amount of red, green, and blue light in the final product through inclusion of resistors in the chip itself. Once the chip is created, it cannot be changed from cool white to warm white or vice-versa because what makes it thus is a slight difference in the areas that were etched out and implanted in the chip.

TheRedneck

I have used LED monitors for most of my day for years and have not developed Macular Degeneration, which is the by-product of blue light. LED's in bulbs in the home and computer monitors don't cause eye damage that I am aware of as well as stated by eye specialists.

The LEDs that do cause damage are the high intensity ones used in cars and for growing plants. I have seen cars on the road with the LED headlights and they are blinding and should be outlawed.

a reply to: TheRedneck

Redneck spoke too soon.

One version of the white LEDs does indeed use a phosphorescent coating which is activated by UV LED light. That was, according to my info, a design used in earlier LEDs before they managed to get the elements close enough to overcome the color shadowing effect.

TheRedneck