Miles Johnston - LED Street Lighting updated on 26th October 2013

[ktlight]

http://www.youtube.com/watch?v=Fa2vqYDU444&feature=youtu.be

"Miles talks about what we need to find out about the new LED street lighting being put into cities, for instance how to know whether they are safe.

Miles happened to see a faulty LED street light on his way home last night and recorded it on his mobile phone. This illustrates what a faulty LED street light looks like and is tagged to the end of this video, and Miles captioned it."

[Agape]

Yes it's very important piece of information ...read more here http://qz.com/137221/a-plan-to-turn-every-lightbulb-into-an-ultra-fast-alternative-to-wi-fi/

Tell Miles I can't stand the fluorescent and other lights at all, since childhood, we had them in all classrooms , they were in offices, hospitals , all commonly shared places and they kept me blinking and twitching eyes , mum would always ask why do I 'do that', I was not even aware of doing anything .
Same with cameras, computers , and else , it's both the intensity and of course, frequency range that hurts the retina .

See also here :

http://www.dailymail.co.uk/health/article-2324325/Do-environmentally-friendly-LED-lights-cause-BLINDNESS.html

Do 'environmentally friendly' LED lights cause BLINDNESS?



Spanish research has shown that blue LED light can irreparably damage the cells in the eye's retina
This is not the first time energy-saving bulbs have been criticised - fluorescent bulbs emit dangerous UV light


Eco-friendly LED lights may damage your eyes, according to new research.
A study has discovered that exposure to LED lights can cause irreparable harm to the retina of the human eye.
LED lights have been touted as a super-efficient alternative to traditional bulbs because they use up to 85 per cent less energy and each bulb can last up to 10 years.
In April, Philips, the world's biggest lighting maker, reported a 38 per cent jump in LED light sales from last year.


They are already widely used in mobile phones, televisions, computer screens and can also be fitted as a replacement for traditional lighting in the home.
LEDs are much more expensive that traditional bulbs - costing around £25 for an equivalent 100w compared to around £1 for an incandescent bulb - although manufacturers claim that consumers make their money back because the use such little energy.


The government announced it was phasing out incandescent bulbs in 2007 after an EU directive banned their use. The 100w bulb was the first to go in 2009 and lower wattage bulbs continue to be phased out gradually.
The ban caused public outrage as customers were forced to spend large sums of money on lighting that not only gave an unpleasantly 'cold' light but also caused some people to report symptoms of itchy skin and headaches.
The government's Enhanced Capital Allowance Scheme, which was brought in to help cut UK carbon emissions, is also pushing the use of LED lighting by offering businesses added tax relief if they use LED and other low-energy bulbs.
Dr. Celia Sánchez-Ramos, of Complutense University in Madrid and who led the study, explained that light from LEDs, or light-emitting diodes, comes from the short-wave, high-energy blue and violet end of the visible light spectrum.


...




Working on computer is one example where I find human technologies harmful . The pain in your eyes once it sets in is not easy to 'undo' , sometimes for days .
It's difficult to focus on what you want to do through this .

[Tesseract]

Haha,

(thanks for posting, but I have to laugh, quite a lot, might share it with the electrical engineers at work...)

Perhaps email Miles and politely tell him that D stands for diode. A diode allows current flow in one direction only, that means a potential bias of one direction only is effective - that means DC not AC input signal is used for LEDs. LEDs are inherently DC devices, they are powered by a 'driver' that provides the correct constant voltage. The AC signal from the mains just has to be converted to DC with a rectifier or something. LEDs require a DC voltage of a certain minimum magnitude (about 1.5 to 3 V) to produce light (note Miles's concerns about the need for DC operation at ~4.30 and ~7.35).

Anyway, you could pulse them with a DC square wave input, if you wanted to, so if Miles's concerns are valid (god help us), DC operation doesn't mean much in the way of disabling flashing. You could also pulse other light sources, if you wanted to.

Before someone points it out for me, yes, people are working on AC powered LED systems, even flashing ones, but they are still DC when you reduce it down as far as I know. But, again, making them flash should be a fairly trivial matter whether AC or DC.

Better finish this before I lose control of my fingers, couple of LEDs staring me down right now..

[Tesseract]

I remember I used to ride my bike below a certain set of street lights, when I had the speed right it looked like the bike wheels were not turning around, or were turning slowly backwards. And, my legs always got tired, but until now I thought it was just because I was unfit.

[Tesseract]

Synchronicity moment coming on; in another city every day I used to ride my bike past a large cemetery in which the inventor of the strobe light was buried.

[Tesseract]

My first university physics experiment involved a strobe light, a turntable and a ball bearing. Physicists have the best rave parties.

Sorry:

:focus:

[Snowflower]

Well, hell. I have been switching all of my lights to LED because I found out how bad compact fluorescents are. So there's now another cognitive dissonance in my life. I know now that looking at my iPad screen is damaging my retinas. I know I'm not going to stop looking at it. I wonder if there is a see-through shield to wear over glasses to protect my eyes? But that doesn't help with room lighting. Candlelight?

[Tesseract]

Well, hell. I have been switching all of my lights to LED because I found out how bad compact fluorescents are. So there's now another cognitive dissonance in my life. I know now that looking at my iPad screen is damaging my retinas. I know I'm not going to stop looking at it. I wonder if there is a see-through shield to wear over glasses to protect my eyes? But that doesn't help with room lighting. Candlelight?

Do you prefer to burn your retinas or burn down your house?

[Flash]

Well, hell. I have been switching all of my lights to LED because I found out how bad compact fluorescents are. So there's now another cognitive dissonance in my life. I know now that looking at my iPad screen is damaging my retinas. I know I'm not going to stop looking at it. I wonder if there is a see-through shield to wear over glasses to protect my eyes? But that doesn't help with room lighting. Candlelight?

Do you prefer to burn your retinas or burn down your house?

Do we really burn down our retina???? where are the research, I did the same thing, changed some lights, my office amongst others, for LED. And the impulses, wow. I am a complete ignorant into engineering and lighting, Tesseract, you can laugh, but please, help.

[Tesseract]

Well, hell. I have been switching all of my lights to LED because I found out how bad compact fluorescents are. So there's now another cognitive dissonance in my life. I know now that looking at my iPad screen is damaging my retinas. I know I'm not going to stop looking at it. I wonder if there is a see-through shield to wear over glasses to protect my eyes? But that doesn't help with room lighting. Candlelight?

Do you prefer to burn your retinas or burn down your house?

Do we really burn down our retina???? where are the research, I did the same thing, changed some lights, my office amongst others, for LED. And the impulses, wow. I am a complete ignorant into engineering and lighting, Tesseract, you can laugh, but please, help.

Congratulations for being in the avante garde of office lighting. Although they may be able to damage retinas/cells in the lab, I am not too worried about LED lightbulbs personally even if some of them do emit some short wavelength light. If I had a baby in the house that for some reason might want to stare at LED lights directly, I might go for a softer incandescent just to be safe - or just use a lamp shade. Or, if the light was uncomfortably bright, I would change it.

If I were building a house I would choose the most energy efficient lighting which is now LED. I would choose chemiluminescent panels if I had some money to throw around... Compact fluorescents are a bit of a worry, when you break them, since they can contain mercury.

I would be amazed if the output from a LED lightbulb was more harmful to the eye than sunlight, or even close. I found the image below which compares spectral output - the 400 nm and lower are the problem wavelengths. If I were concerned I would look at more technical data and any eye-health studies that have been done. If I had LED lighting I would simply not stare directly at the light bulbs. The supplier of any LED lighting products should be able to provide the spectral output for their particular product.

Is there an issue when using LEDs for an entire human lifetime? It is a serious question, as Agape's article points out, but there are a lot of variables, and I don't think anyone can answer that for certain. I certainly can't. Short wavelength light can't be avoided entirely, and it probably shouldn't be. Personally I am more worried about the mould in my walls and carpet, the chemicals in the water and the things I am exposed to at work.

23382

[Snowflower]

Tesseract, what about the lighting on the computer screen or ipad? Isn't it LED source? We are staring straight at it.

[Taurean]

Infrasound

Apparently the Human eye resonates at 18hz and is thought to produce a wide range of weird effects when subjected to such low frequencies.

http://en.wikipedia.org/wiki/Infrasound

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA030476&Location=U2&doc=GetTRDoc.pdf

[Flash]

the part on infrasound and the impact on the eye is quite interesting


wikipedia: Suggested relationship to ghost sightings[edit]

Research by Vic Tandy, a lecturer at Coventry University, suggested that an infrasonic signal of 19 Hz might be responsible for some ghost sightings. Tandy was working late one night alone in a supposedly haunted laboratory at Warwick, when he felt very anxious and could detect a grey blob out of the corner of his eye. When Tandy turned to face the grey blob, there was nothing.

The following day, Tandy was working on his fencing foil, with the handle held in a vise. Although there was nothing touching it, the blade started to vibrate wildly. Further investigation led Tandy to discover that the extractor fan in the lab was emitting a frequency of 18.98 Hz, very close to the resonant frequency of the eye given as 18 Hz by NASA.[34] This was why Tandy had seen a ghostly figure—it was an optical illusion caused by his eyeballs resonating. The room was exactly half a wavelength in length, and the desk was in the centre, thus causing a standing wave which caused the vibration of the foil.[35]

Tandy investigated this phenomenon further and wrote a paper entitled The Ghost in the Machine.[36] Tandy carried out a number of investigations at various sites believed to be haunted, including the basement of the Tourist Information Bureau next to Coventry Cathedral[37][38] and Edinburgh Castle.[39][40]


Taurean, was this your thesis in 1976?? Or did you work on something like this? Interesting.

[Taurean]

TBH, I'd never heard of Infra-sound until yesterday. - synchronicity ;)

I was reading about the "Dyatlov Pass" incident at the time.

The thesis is the NASA pdf reference [34]

Another interesting fact to emerge regarding the Chelyabinsk Meteor in Feb 2013 was "The meteor explosion produced the largest infrasounds ever to be recorded by a United Nations monitoring system,[41] so great that they reverberated around the world several times, taking over a day to dissipate.[42]"

http://en.wikipedia.org/wiki/Chelyabinsk_meteor

[Tesseract]

Tesseract, what about the lighting on the computer screen or ipad? Isn't it LED source? We are staring straight at it.

Indeed, but with the lights off my computer screen doensn't really illuminate the room much, so the intensity must be quite low. Plus the spectral output will depend on what image is on the screen at the time. I suspect the glass(?) that forms the surface of the screen should also block any UV that might be being emitted internally.

[Agape]

Well, hell. I have been switching all of my lights to LED because I found out how bad compact fluorescents are. So there's now another cognitive dissonance in my life. I know now that looking at my iPad screen is damaging my retinas. I know I'm not going to stop looking at it. I wonder if there is a see-through shield to wear over glasses to protect my eyes? But that doesn't help with room lighting. Candlelight?

The iPad Retina display should be actually least harmful of all, greater the resolution less strain on eyes comes to effect .
It's generalised advice but avoid 'blurred' screens and low resolution devices , they cause the most problem .

[Soul Safari]

This is strange!

Essex has just implemented a total shutdown of street lights after 12 midnight. Trust me walking home at night is a complete nightmare (total blackout)

They are saying that the council can't afford the money to pay for lighting. People have been in disgust and the councll has binned every letter of complaint. MPs have even spoken out and said we should 'grow up' to the fact of the the street light shutdown. I guess time will tell when some doughtnut comes up with the idea of cheaper more eco friendly lighting but REALLY we're getting LED's.

Watch this space..

[Flash]

you have to go back to lantern in Essex it seems

In fact, every Citizen should carry it a lantern around in protest - back 100 years

I hope the county will be sued when the first girl will be raped because rapist have taken the opportunities of dark Streets. And here I am talking of all evening and night workers coming homes, kids after party coming home, etc.

[Vitalux]

I'm really happy to see this LED technology come into the street lights.
They certainly use a lot less energy and they have an incredible life span compared to the old metal halide system.
Everything changes always and it is good to see new improved systems coming on board.
Thank you for sharing OP.