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New York City Street Lights To Go LED

Soulskill posted more than 5 years ago | from the big-apple-lite dept.

Technology 303

eldavojohn writes "Wired has a short piece on NYC's new street light project. I don't think we need to belabor the many benefits that LEDs hold over traditional light bulbs, but the finishing touches are being addressed, and they will hopefully be put into place sometime next year. This design won a competition back in 2004, and OVI has been whittling down the prototypes. At $1.175 million, this sounds like a pretty cheap deal considering the DOE forked over $21 million to 13 R&D projects along the same lines."

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flicker crashes (4, Interesting)

goombah99 (560566) | more than 5 years ago | (#26181331)

The thing that is awful about led lamps is that most of them are run straight off the AC voltage and have massive 100% brightness flickers. If you are moving it's like a strobe. You don't see it in car lights since they are run off DC. but most, perhaps not all, AC socket lamps I've seen have really bad flicker.

I also how they have secondary lenses since LED's can be very directional the way they are typically resin cast.

Re:flicker crashes (1)

KudyardRipling (1063612) | more than 5 years ago | (#26181351)

The LED tail lights are PWM controlled and I see that flicker! Wonderful! Moving epilepsy triggers on the roads and now stationary ones as well!

Re:flicker crashes (1)

corsec67 (627446) | more than 5 years ago | (#26181495)

Yeah, that fucking annoys me as well. Why can't they use something like 1kHz, not 60Hz? Or can I put a strobe light that has been colored red on the back of my car?

A cars electrical system runs at 12v DC, more or less, DC being the important thing there.

They can choose any frequency they want for the tail lights, so for the parking lights, which are normally used at night, they choose something around 60-70Hz. It is like they are trying to be annoying.

I was once in a Lexus that used that same system for the lights in the dash as well. I couldn't look at any of the dials or indicators in that car, so it was a good thing I wasn't driving.

Re:flicker crashes (0, Flamebait)

morgan_greywolf (835522) | more than 5 years ago | (#26181595)

They can choose any frequency they want for the tail lights, so for the parking lights, which are normally used at night, they choose something around 60-70Hz. It is like they are trying to be annoying.

I dunno. Lots of people claim they can see the 'flicker' on a CRT with a 70 hz vertical refresh rate. If I turn my head wayyyyyy to the left or right, putting the monitor in my peripheral vision, I might be able to see the flicker on a 60 hz, but never at 70 hz or higher.

Then again, there's also a bunch of crazy people that say they can hear LCD flat panel displays making a buzzing noise. I can't hear that either.

Re:flicker crashes (3, Insightful)

corsec67 (627446) | more than 5 years ago | (#26181703)

I dunno. Lots of people claim they can see the 'flicker' on a CRT with a 70 hz vertical refresh rate. If I turn my head wayyyyyy to the left or right, putting the monitor in my peripheral vision, I might be able to see the flicker on a 60 hz, but never at 70 hz or higher.

Just because you don't have some trait doesn't mean that other people don't. In this case, that trait is how fast your eyes can see. Congratulations, you have slower eyes.

I am one of those people. It isn't just "flicker", I can see the image-black-image-black pattern of the CRT at 60Hz without doing any tricks like waving my hand in front of the monitor or using the side of my vision.

I can't stand to be in the same room as a CRT monitor running at 60Hz, it is almost physically painful to see. When I had a CRT I had to run it at 85Hz to be able to use it for any period of time, but still had to make the text white on black, turn the brightness down, and such.

If it doesn't bother you, then imagine replacing every CRT with a strobe light running fast, as bright as the monitor. That would be annoying and distracting, right?

Imagine that tail lights of cars and buses were red strobe lights. Around here, that is actually a reality, with most of the new buses and some new cars having tail lights running at 60Hz. It is extremely obvious to me, where I can instantly point out which cars in a long line have blinking LED tail lights.

Pants crashes (0)

Anonymous Coward | more than 5 years ago | (#26181855)

"Just because you don't have some trait doesn't mean that other people don't."

I have two dongs.

Re:flicker crashes (3, Informative)

kc8apf (89233) | more than 5 years ago | (#26182223)

Cars and buses with LED tail lights are not running them at 60Hz. Nor are they being pulsed at any rate. The electrical system in a car is 12V DC. The LED assembly is either designed with enough LEDs in series such that the forward voltage drop over the set is 12V (roughly 10 LEDs) or they are in parallel with a buck-style switching power supply in front of it.

Now, before you go on about how the switching power supply causes flicker, you should research how they work. You will find that for cost and size reasons, it is better to run a buck topology as fast as possible. 250kHz, 500kHz, and 1MHz are common frequencies. Of course, the output from the switching portion is put through a LC filter such that the voltage ripple is reduced to a small percentage of the target output voltage. Besides, LED brightness is controlled by current. Even a 5% voltage ripple on a 2V output would trigger a few lumens of brightness difference.

So, if you are seeing flicker in car and bus tail lights, then you can see a 250kHz "flicker" with an average brightness delta of a few lumens. If you can, I'm sure there are plenty of researchers who would love to talk to you as you are the only person on the planet who can.

Of course, since cost is the driving factor in these types of devices, they probably aren't using the switcher at all and thus there is _no_ flicker due to electrical reasons. You are probably being more affected by the directionality of the LEDs and the lenses used being vibrated by the engine at idle speeds. You get the same effect watching a motorcycle headlamp on a rough road. The light isn't flickering, it is just vibrating enough that the beam is falling in and out of your eye.

Re:flicker crashes (0, Troll)

Creepy Crawler (680178) | more than 5 years ago | (#26181749)

'say they can hear LCD flat panel displays making a buzzing noise'

Yeah, I can hear that, and its not what you think. Its usually a transformer charging up or some other form of high-voltage circuit. When we used to have a 36 inch CRT tv, I could hear it on across the house and 2 floors away cause of that damned buzz. Now we have some widescreen (tube tv blew cause of brownout and wasnt surge protected) which I can only hear faintly in the next room..

The tubes also were lower frequency. The recent LCD's are more of a quick crackle and gone.. Perhaps its just too high for me to hear.

Re:flicker crashes (1)

enrgeeman (867240) | more than 5 years ago | (#26182247)

I can hear that buzzing noise, but only on those cheap screens. Anything actually decent, I can't hear. Which is a good thing, because of how often i'm in front of them. To each his own.

Re:flicker crashes (1)

Clay Pigeon -TPF-VS- (624050) | more than 5 years ago | (#26181519)

At least the gene pool will lose some of its mud.

Re:flicker crashes (1)

RancidPeanutOil (607744) | more than 5 years ago | (#26181627)

They make awesome trails when you drive at night, though - oh wait, is it bad to simulate the effects of pharmocological hallucinogens on public streets? Maybe it's not such a good idea then. If only they could make them so that they both flicker and hum - to match current flourescent lighting.

Re:flicker crashes (4, Interesting)

digitalunity (19107) | more than 5 years ago | (#26181401)

Assuming the line voltage is run through a full wave bridge rectifier, there would be a 120 Hz flicker, imperceptible to most people. Toss a large capacitor across that DC output and you've got dramatically less ripple.

Your directionality comment is apropos. It's also worth noting that some people don't like the light spectrum output on white LED's. Personally, I prefer the pink tint from high pressure sodium lamps.

Re:flicker crashes (3, Insightful)

goombah99 (560566) | more than 5 years ago | (#26181435)

Assuming the line voltage is run through a full wave bridge rectifier, there would be a 120 Hz flicker, imperceptible to most people. Toss a large capacitor across that DC output and you've got dramatically less ripple.

true but then you also have 100 times the surge current when you turn them on, or a slow turn on.

What you say is of course obvious to any EE, and yet i've never actually seen a single 120v LED lamp made that way. One wonders why.

Re:flicker crashes (3, Insightful)

digitalunity (19107) | more than 5 years ago | (#26181697)

These aren't headlights, they're street lamps. Do you really care if it takes them 3 minutes to warm up?

And even assuming they have ballasts featuring accelerated warm-up, the starting current will still be as much as double the normal operating current requirements. Really though, the starting current is negligible in the grand scheme of efficiency comparisons.

I'm not an expert on line voltage LED units designed to replace incandescents, but I would imagine including a bridge rectifier and capacitor would increase the cost and pose significant design constraints due to the components size.

Re:flicker crashes (3, Informative)

Bruce Perens (3872) | more than 5 years ago | (#26181781)

You don't have to have a bridge rectifier. Just run two strings of LEDs with opposing polarity, in parallel, and you have the light of one string containing the same number of LEDs, but at 120 Hz. What the bridge rectifier gains you is a fuller duty cycle, rather than one something less than 50%, and just more light from each LED. Whether you want that or not depends on heat.

Re:flicker crashes (1)

wasmoke (1055116) | more than 5 years ago | (#26181829)

Now, I only pulled a B in Physics, but couldn't you fix the current surge with an inductor? I won't pretend to be an expert on circuits, but would that not fix the problem?

Re:flicker crashes (0, Flamebait)

Tanktalus (794810) | more than 5 years ago | (#26181949)

That'll just slow down the warm-up by delaying the current draw. By itself, an inductor simply turns the current 90 degrees from the voltage, which is generally a bad thing for efficiency. Combine it with a capacitor (which turns the current 90 degrees the other way), and you might be getting somewhere. Combine it with a bunch of other logic (parallel/series components), and you end up with ... basically complexity.

Seriously, if you start your thought process with "I only pulled a B in something, but couldn't you fix ..." when the people working on it have bachelor's degrees (or master's or PhD's) in the subject area, it probably would not solve the problem

-- got an EE degree over 11 years ago, and never used it in the field, so details are hazy.

Re:flicker crashes (1)

itzdandy (183397) | more than 5 years ago | (#26181509)

I personally get nauseous from any perceivable flicker and am very sensitive too it. I only last about 5 minutes in regular florescent lighting.

I know that I am ultra sensitive but there are many people with various degrees of sensitivity to such flicker.

I also dislike pure white light. It is uncomfortable to look at anything in pure white light.

LED is a great technology but despirately needs to develop natural light replacements and/or incandescent replacements. A couple million years of evolution has tuned my preference of lighting.

OT: sig (1)

XanC (644172) | more than 5 years ago | (#26181887)

Your sig's link appears to be broken.

Re:flicker crashes (1)

noidentity (188756) | more than 5 years ago | (#26181585)

Assuming the line voltage is run through a full wave bridge rectifier, there would be a 120 Hz flicker, imperceptible to most people.

The issue isn't just direct flicker perception; secondary effects like what a moving object looks like can make flicker of 120 Hz visible. Under normal light, moving objects leave a blur, not a path of distinct afterimages.

Re:flicker crashes (4, Informative)

amRadioHed (463061) | more than 5 years ago | (#26181449)

There are plenty of LED traffic lights around me and I've never noticed any flicker. I imagine it isn't a problem.

Re:flicker crashes (2, Insightful)

RSCruiser (968696) | more than 5 years ago | (#26181725)

I don't notice any flicker as well. I have noticed that some lights have blocks of LEDs failing rather quickly after installation though. Entire sections of turn arrows and squares in circular lights that have gone out look rather weird. It may be a brand/manufacturer issue though since I see this in the larger metro area but not in the suburb where I live even though the suburb has had them longer.

Makes you wonder if they'll have the same issues with chunks failing in these lights.

Re:flicker crashes (3, Informative)

a1englishman (209505) | more than 5 years ago | (#26182087)

The biggest problem with LED traffic lights is that the greens are REALLY bright. You'll be shocked, especially at night how bright the damned things are. In SoCal, we have LED traffic lights everywhere.

Planned For (0, Offtopic)

maz2331 (1104901) | more than 5 years ago | (#26181461)

Dammit Man, you gave away the plan!

It's not to cause crashes, just to make drivers swerve so that they can be pulled over and ticketed or searched for that 0.00001 microgram of coke on every dollar bill in circulation.

No swerve, no probable cause. Means the ter'ists can just run rampant and kill us all. /sarcasm

Re:flicker crashes (1)

camperslo (704715) | more than 5 years ago | (#26181635)

Instead of what sounds like raw-rectified power, they should have some intelligent (and too fast to see) flicker. Since LEDs could easily handled modulated power to send a data stream of something...

hmmm... car tail lights could too, but what to say?

Re:flicker crashes (1)

Bruce Perens (3872) | more than 5 years ago | (#26181757)

LEDs for this sort of light would be surface-mount - it makes automated assembly possible. And thus they would not generally have the hemispherical plastic dome you're used to from the leaded components. They'd probably just have a transparent coating that would not bend the light much.

Re:flicker crashes (5, Informative)

Low Ranked Craig (1327799) | more than 5 years ago | (#26181897)

Well, they have been testing these lights in my home town of Scottsdale, and they have three different types installed along one stretch of road way. They are super bright, and there is no flicker whatsoever.

The fact that they are directional is an advantage in this case since they are meant to throw light in a cone shape. The ones I've seen have no secondary lens. If there is any covering at all it is completely transparent glass.

Personally I like them because the light is white, not the orange of sodium vapor. Reminds me of when I was a kid before the move from mercury vapor to sodium vapor...

Wow... (-1, Offtopic)

Rog-Mahal (1164607) | more than 5 years ago | (#26181335)

My first...first post. I guess I'd better say something sage. Welcome Light-Emitting-Diode Overlords!

There will always be a vulnerability (0, Offtopic)

KudyardRipling (1063612) | more than 5 years ago | (#26181337)

EMP generators, anyone? How about Mooninite patterns?

Re:There will always be a vulnerability (1)

the_fat_kid (1094399) | more than 5 years ago | (#26181985)

this is an unbearable strain but I'm doing it as hard as I can...

Giant LED light bulbs (3, Interesting)

pwizard2 (920421) | more than 5 years ago | (#26181345)

This is something I've been wondering about for awhile. LEDs (especially the white ones) are really bright for being so small, and they don't have that yellow tint that incandescent bulbs do. Compact florescent bulbs are nice, but they aren't perfect for every situation. I'm not an expert on the subject, but I've always wondered why they don't make giant LEDs that can replace ordinary light bulbs. It seems like 220 AC would be more than enough to power them.

Re:Giant LED light bulbs (2, Informative)

Anonymous Coward | more than 5 years ago | (#26181375)

It's being worked on. Basically the issue holding them back is cost/brightness. Given the inevitable lowering of costs of all things technological and the toxicity of CF-bulbs I think it's just a matter of a few years before LEDs take on the consumer lightbulb market in a big way.

Re:Giant LED light bulbs (0)

Anonymous Coward | more than 5 years ago | (#26181561)

Heat is also a major issue. LEDs generate less heat than an equivalently bright incandescent, but it's a lot harder to dissipate it, and they break when they get too hot.

Re:Giant LED light bulbs (3, Interesting)

cathector (972646) | more than 5 years ago | (#26181639)

> and they break when they get too hot.

actually, high-power LEDs such as Philips's Luxeon series are quite robust in the face of surprising amounts of heat. I've run enough current through them so that they melted their soldering several times, and while its true their efficiency declines with heat, they suffered no permanent damage. When you put an amp and half through one of those suckers, they're literally stunningly bright.

Re:Giant LED light bulbs (3, Informative)

goombah99 (560566) | more than 5 years ago | (#26181387)

uh... because they do and you can buy them [google.com] .

Re:Giant LED light bulbs (3, Interesting)

Anonymous Coward | more than 5 years ago | (#26181443)

That's not what he means. The replacement 120v led lamps are a collection of a bunch of little white led's. Why can't they make a single led the size of a lightbulb instead of 100 small led's.

Is it possible to make a single, huge led?

Re:Giant LED light bulbs (3, Informative)

goombah99 (560566) | more than 5 years ago | (#26181469)

You can buy a single 5 watt led that is the same brightness as a 50 watt incandesscant.

Re:Giant LED light bulbs (1)

UltimApe (991552) | more than 5 years ago | (#26181899)

the actual light producing part of an LED is tiny, even in the high powered ones... part of the reason that they don't make huge ones is that the actual light producing area is very small, and thus has a higher heat/area ratio... while they are effectively less heat than an incandescent, the concentration of heat is much higher, and requires larger heatsinks to wick that heat away into a larger surface area. The "bulb" of an LED is really only there to disperse the light.

Re:Giant LED light bulbs (5, Insightful)

Waffle Iron (339739) | more than 5 years ago | (#26182359)

Why can't they make a single led the size of a lightbulb instead of 100 small led's.

Is it possible to make a single, huge led?

I don't know. Maybe it's the same reason that they can't make a tungsten filament the size of a whole light bulb. Instead, they keep selling us a tiny wire the size of a pubic hair surrounded by a huge void filled with argon gas. This has been going on for well over a century, and they never seem to fix it.

Re:Giant LED light bulbs (1)

simcop2387 (703011) | more than 5 years ago | (#26181389)

as far as giant ones, my understanding is that they can't scale like that, but as far as replacement bulbs go for normal light fixtures, google brings up this, http://www.theledlight.com/ [theledlight.com] i'm sure there are LOTS of others too.

Re:Giant LED light bulbs (3, Informative)

KudyardRipling (1063612) | more than 5 years ago | (#26181395)

The white LEDS are doped to generate three distinct colors of light (R,G,B) whose combination yield a very cold blueshifted white light (>6500 K). If one seeks to use these for video, better check to see if the camera works well with such light.

Re:Giant LED light bulbs (4, Interesting)

dgatwood (11270) | more than 5 years ago | (#26181609)

Yeah. I've noticed that. What I don't get is why they choose to set the color temperature that way. Red LEDs are extremely cheap compared with producing light at the other end of the spectrum. Why in the world would they balance them towards the blue (expensive) end of the spectrum when that is both more expensive and visually unpleasant? About the only thing I can imagine about the current LED designs is that they were designed to be used in combination with standard incandescent bulbs. If you blend the two, you should get a fairly nice looking light spectrum, albeit probably a bit heavy in the yellows....

I'd buy LED lights instantly if they actually used three emitters. Unfortunately, most don't. They use two---one yellow, one blue. Because the yellow LED has a relatively narrow light spectrum compared with an incandescent, you end up with basically no light output down near the bottom of the visual spectrum. The result is light that is downright unpleasant to deal with in every way. The bluish light makes it hard to see color accurately, makes colors not reproduce well in photography or video, and really isn't good for you mood-wise. Basically, the current crop of LED lights have all the problems of CFLs except the mercury (well, and the LEDs should last a lot longer, I believe).

The question, then, becomes this: "When are we going to see properly designed white LED bulbs?"

On the other hand, while they suck for homes, the existing LED lights are perfect for street lights. First, there was one experiment [psychcentral.com] that suggests that suicides and crime may decrease when street lights are replaced with bluish lighting. Second, the color temperature of blue LEDs are virtually indistinguishable from the mercury vapor lights (~6000K) that are already used in a lot of places.

Re:Giant LED light bulbs (2, Informative)

Bo'Bob'O (95398) | more than 5 years ago | (#26181997)

The company I work for has actually done a good amount of research on the technologies available for high efficiency lighting right now and they do indeed make warmer white LEDs. They look pretty nice and have an adequate CRI, however, their efficacy is poor enough compared to the cool white LEDs that they are in fact only about as efficient as compact florescent.

I think it has to do with the fact that the visible light generating part of white (and blue) LEDs are phosphors pumped by what is actually a ultra-violet LED. Now I might be wrong on this part, but I think that those larger wavelength colors are less and less efficient to make this way. I'm not sure simply putting in a red or amber LED would fill in enough of the spectrum to generate a pleasant light.

Re:Giant LED light bulbs (2, Insightful)

dgatwood (11270) | more than 5 years ago | (#26182099)

Could be, but an LED that uses phosphors eliminates any interest in my book because it means the color spectrum is a spiky mess.... :-) Either way, though, I'd gladly accept much less efficiency to get better light quality. I hate CFLs (even the so-called daylight CFLs) so much that I'm planning to start stockpiling incandescent bulbs soon in preparation for the U.S. ban on them. That cold, lifeless lighting just really bugs me.

Re:Giant LED light bulbs (1)

Jah-Wren Ryel (80510) | more than 5 years ago | (#26182265)

Could be, but an LED that uses phosphors eliminates any interest in my book because it means the color spectrum is a spiky mess.... :-)

That is the way all white LEDs work.
If you want something else, you will need an RGB array of leds - those exist too, but they cost more to manufacture and can't always be used to substitute for incandescent since some applications require a single point source.

Re:Giant LED light bulbs (1)

dgatwood (11270) | more than 5 years ago | (#26182313)

You can always put a more than one LED emitter in a single epoxy package. Tricolor LEDs are a red and green emitter inside a single clear shell. Those are at least as close to a point source as you'll ever get with a glowing filament....

Re:Giant LED light bulbs (1)

pipingguy (566974) | more than 5 years ago | (#26182373)

there was one experiment [psychcentral.com] that suggests that suicides and crime may decrease when street lights are replaced with bluish lighting.

What's the theory behind that?

Re:Giant LED light bulbs (1)

poity (465672) | more than 5 years ago | (#26181471)

They do
http://www.dealextreme.com/products.dx/category.907 [dealextreme.com]
One of many places on the net.

Problem is the light emission is not quite as omnidirectional as CFLs. They may be good for ceiling mount lights, but probably won't work for desk lamps, wall sconces, and such. And as efficient as LEDs are, they still get pretty hot when packed together so tighly (notice the heat sinks).

Re:Giant LED light bulbs (3, Informative)

dlenmn (145080) | more than 5 years ago | (#26181481)

LED light bulbs do exist (they're a bunch of small LEDs, not one jumbo one -- I don't know if that's feasible).

I think you hit on the problem in your post though, power. 220V (or 120V) AC certainly has enough watts, but it's not in a usable form for LEDs. They require direct current (DC) at a much lower voltage. So you need some power conversion electronics to make them work. Then, to make them work efficiently, you need more electronics to regulate the current through them. For a standard electronics project, you just use a resistor, but then you're wasting power (to the tune of P=R*I^2). Off the shelf components that regulate the power more efficiently exist, but it adds expense.

Fluorescent lights need some electronics to work too, but I don't think they're as complicated (and are thus, cheaper). Cost is a big factor here, because old incandescent light bulbs don't cost much to purchase.

Re:Giant LED light bulbs (2, Informative)

KudyardRipling (1063612) | more than 5 years ago | (#26181689)

The type of power supply used in LED lighting is called a 'buck/boost' converter. It is a switching supply that merely PWM's the filtered line voltage down at high frequency (40~60KHz) to the operating voltage and current of the load The difference between this and a standard switching supply is that no isolated secondary circuit is required and thus the only 'large' components are the rectified line voltage filter caps, load filter caps, choke and heatsink mounted FETs or IGBT's. This also neatly eliminates the surge problem because the operating frequencies of said supply is high enough to keep the caps relatively small.

one million? (1)

z-j-y (1056250) | more than 5 years ago | (#26181383)

there is no way they can change all the lights for one million.

Re:one million? (4, Informative)

shawb (16347) | more than 5 years ago | (#26181513)

FTA, the ~$1million is for building and testing six working prototypes. The design will then be added to a catalog the city uses, and they can then install them as they see appropriate.

Unscrew the locks from the doors (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26181391)

I once kenw a girl from New York City and she would not LOVE me because she is a GODLESS HORE. These lights will do NOTHING I prefer to live under a LOG where there is some chance of interaction with the spirit that animates alkl things on the EARTHk, because you do not see it bwecause it means yhou are a GODLESS HORE and should go to IRAN and see if they like you "there" , you smell like a GOAT

I hate leds!! (-1, Flamebait)

Anonymous Coward | more than 5 years ago | (#26181407)

LED lighting looks like total crap. Some can even ruin your vision (See blue light hazard)

I believe LEDs are *NOT* even the most energy effecient solution... Lagging behind CF, carbon nanotube lighting (Still vaporware) and RF based systems that have been avaliable for decades.

Re:I hate leds!! (2, Funny)

KudyardRipling (1063612) | more than 5 years ago | (#26181555)

Blue Light hazard? No wonder my eyes hurt after shopping at K-Mart.

Re:I hate leds!! (3, Informative)

digitalunity (19107) | more than 5 years ago | (#26181601)

The lighting product manufacturers quote efficiency in lumens-per-watt(lpw). What they don't shove in your face in marketing is that the devil is in the details.

CFLs, LEDs, incandescents, HPS and metal halides all have drastically different spectrum outputs. Incandescents have a very broad spectrum but their lpw is astonishingly low.

CFLs have as much as 80 lpw, whereas MH and LEDs are currently at about 100 and HPS can be even higher(around 140 lpw initial, which declines over time). LEDs have the potential to be higher than HPS but across the lifetime of the HPS bulb the LED may end up with a higher average lpw and definitely much longer service life.

There are CFL's with a broader spectrum but they're less efficient. While not completely monochromatic, there is a big spectrum spike in reds and yellows for HPS bulbs. Most people find this light to be soothing. Metal halides have a broader spectrum than HPS but are less efficient than even fluorescents. There are new white LEDs in research that produce as much as 145 lpw, but these are not commercially produced yet. Philips produces a 115 lpw white LED which is available in large quantities. You're right about the blue light hazard though - phosphor based white LEDs have a large spike around 465nm.

Interested in reading more about Lighting? Read the book the pot growers read. They have the best lighting money can buy. The Best of the Growing Edge [google.com]

Steve Jobs is a 99 lb weakling (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26181411)

Somebody, quick, feed the man.

How (4, Funny)

no-body (127863) | more than 5 years ago | (#26181433)

many NewYorkers does it take now to change a light bulb?

Re:How (1)

KudyardRipling (1063612) | more than 5 years ago | (#26181465)

The answer must contain at least one expletive.

Re:How (2, Funny)

Kashell (896893) | more than 5 years ago | (#26181473)

2 New Yorkers. One to install the lightbulb, and one to mug him for the dead light bulb afterwards.

Re:How (5, Funny)

morgan_greywolf (835522) | more than 5 years ago | (#26181535)

What's it to you, pal?

What's (1, Funny)

Thing 1 (178996) | more than 5 years ago | (#26181729)

it to you pal?

(Posting this because you missed out on the subject/comment flow...)

Re:How (1)

no-body (127863) | more than 5 years ago | (#26182135)

What's it to you, pal?

Almost - more correct Answer:

Q: How many New Yorkers does it take to screw in a light bulb?
A: None 'o yo' fuckin' business!

With LED's, nowadays - it would be something like that:

A: None - all got fuckin' stolen

Re:How (2, Funny)

LoRdTAW (99712) | more than 5 years ago | (#26181745)

None. They don't work because someone stole all the copper wire.

Seriously, this happens all the time in the parks.

Re:How (1)

jellomizer (103300) | more than 5 years ago | (#26181947)

None, the union forbids them from doing work... However they may offer you a favor if you give them a couple of ben franklins.

The full headline.. (0)

Anonymous Coward | more than 5 years ago | (#26181453)

"New York City Street Lights To Go LED on Friday December 19, @11:15PM"

Well, that's pretty quick work.

Isn't HPS more efficient? (1, Informative)

Anonymous Coward | more than 5 years ago | (#26181501)

Aren't LEDs less efficient for white light, compared to current streetlights with HPS? Wikipedia says 150 lumens/watt for HPS and only 10-90 for white LEDs.

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

Re:Isn't HPS more efficient? (4, Insightful)

hardburn (141468) | more than 5 years ago | (#26181653)

Some of the newer LEDs can go above 100 lumens/watt [gizmodo.com] .

One thing about HPS is that it spreads light everywhere, whereas LEDs are more directed, which you want in a streetlight facing down. Omnidirectionalness can be fixed with good fixture design, but most cities use crummy fixtures.

Re:Isn't HPS more efficient? (1)

dgatwood (11270) | more than 5 years ago | (#26181655)

HPS bulbs last about two years. LED bulbs should last at least a decade.

Re:Isn't HPS more efficient? (1)

digitalunity (19107) | more than 5 years ago | (#26181751)

The initial lpw on HPS is usually about 140 but this goes down as you near the end of the bulbs lifetime. LEDs have fairly consistent output until they die.

Re:Isn't HPS more efficient? (4, Informative)

tlhIngan (30335) | more than 5 years ago | (#26181879)

The initial lpw on HPS is usually about 140 but this goes down as you near the end of the bulbs lifetime. LEDs have fairly consistent output until they die.

Actually, LEDs get dimmer as they get used. If they don't fail due to the semiconductor turning into molten metal, they get dimmer and dimmer and dimmer. The 100,000 hour lifetime figure on LEDs is usually the time until 50% brightness (considered to be the point where one would notice the light being dimmer).

There are many reasons for this - degradation of the junction itself, but the semiconductor itself leads to a large index of refraction - a lot of the light in a LED gets reflected back into the semiconductor. And then there's degradation of the epoxy used to seal the LED. All these conspire to make the LEDs much dimmer, and get dimmer over time.

Re:Isn't HPS more efficient? (1)

hrvatska (790627) | more than 5 years ago | (#26181911)

Aren't LEDs less efficient for white light, compared to current streetlights with HPS? Wikipedia says 150 lumens/watt for HPS and only 10-90 for white LEDs.

Might want to check my math, but based on the spec sheet this LED [ledsupply.com] looks like it gets up to 330 lumens/watt .

Won't anyone think of the astronomers? (3, Insightful)

pentalive (449155) | more than 5 years ago | (#26181517)

Are there any major observatories near NYC? (hmm large mountains close to NYC?)

Are these new lights narrow or wide spectrum?

See: http://en.wikipedia.org/wiki/Light_pollution [wikipedia.org]

 

Re:Won't anyone think of the astronomers? (2, Interesting)

hardburn (141468) | more than 5 years ago | (#26181685)

NYC is a lost cause as far as astronomy is concerned, but I have hope that smaller cities and towns will see this and adopt it. LEDs are inheirently directional, whereas most fixtures tend to waste a lot of their light going out and up. So LEDs should be a win for astronomy.

Re:Won't anyone think of the astronomers? (2, Interesting)

adamjaskie (310474) | more than 5 years ago | (#26181737)

LPS/SOX is better, really; the spectrum of LEDs is pretty intrusive to observations. LPS/SOX is also more efficient IIRC, but the bulbs don't last anywhere near as long.

Rumor has it that Cartoon Network will roll it out (0)

Anonymous Coward | more than 5 years ago | (#26181543)

Because of prior experience [cnn.com] in LED street light projects, they would be a natural.

Where did $1.175 million figure come from? (0, Offtopic)

PolarBearFire (1176791) | more than 5 years ago | (#26181623)

$1.175 million sounds way too low to me. That probably wouldn't cover the light poles, LEDs, or installation, let alone replacing all the thousands of existing light poles.

Re:Where did $1.175 million figure come from? (0)

Anonymous Coward | more than 5 years ago | (#26182321)

And why, exactly, would this require putting up new light poles/replacing the existing ones? I mean, I understand that different streetlamp technologies require different pole spacing (I remember when I was a wee lad and streetlights were being installed in my neighborhood, they came around and showed us where the poles would have to be for different types of lamps) but trying to do that in a place like New York is just inane. So, subtract the cost of new light poles, and the cost of replacing existing light poles, and you're left with LEDs and installation... Sure, it's a bit low, but not unreasonably so.

Bad plan in snowy environment... (5, Interesting)

Anonymous Coward | more than 5 years ago | (#26181683)

Here in Portland, OR, we have already started to use LED street lights. And now that we're in a snow storm, these lights aren't working. LEDs don't produce heat (that's why they're efficient). By not producing heat, they don't melt the snow away from them. So all the LED streetlights in Portland are covered in snow and cannot be seen.

The old lights produce enough heat to melt all the snow. Snow in Portland is rare, so it's not that big of a deal. In NY, it's quite the opposite.

Re:Bad plan in snowy environment... (1)

TooMuchToDo (882796) | more than 5 years ago | (#26181779)

So you put a small motor in the lamp head that vibrates the snow off, similar to how a cellphone vibrates. You still make out like a bandit on energy savings.

Re:Bad plan in snowy environment... (1)

Ioldanach (88584) | more than 5 years ago | (#26181937)

Which would do exactly nothing to get the encrusted snow and ice to go away. You have to either heat them or use those tiny windshield wipers on the headlamps that some expensive cars have.

Re:Bad plan in snowy environment... (4, Funny)

Jah-Wren Ryel (80510) | more than 5 years ago | (#26182287)

So all the LED streetlights in Portland are covered in snow and cannot be seen.

Since LEDs are more efficient (more lumens per watt) the colder their tmperature, you can at least take comfort in the fact those snow-encrusted street-lamps are very efficiently lighting up the inside of the snow.

Dark Sky lighting (1)

Strange Ranger (454494) | more than 5 years ago | (#26181709)

I did a "thorough skimming" of every link, and I see no mention of light pollution or dark sky lighting?

WTF?!?! Somebody please tell me I missed it.

LEDs are excellent idea. (0)

Anonymous Coward | more than 5 years ago | (#26181857)

The Department of Transport in South Australia begun a migration to LED powered traffic lights and you should see some of the graphs they've got. MASSIVE reduction in power use.

Re:LEDs are excellent idea. (1)

Rod Beauvex (832040) | more than 5 years ago | (#26181891)

Which you can rest assured will result in a MASSIVE increase in electric rates.

Re:LEDs are excellent idea. (1)

tumutbound (549414) | more than 5 years ago | (#26181943)

Most traffic lights in Sydney are LED. As the old incandescent ones fail, they get replaced with the LED ones. I don't know what sort of power savings are achieved, but I see the repair guys a lot less at the major traffic intersection near me. Unfortunately, the streets lights are still either sodium or mercury vapour.

Will they turn on and off when you walk by? (0, Offtopic)

RevWaldo (1186281) | more than 5 years ago | (#26181889)

They're not proper street lights if they don't.

Are LEDs in those impossible to see stop lights? (0, Offtopic)

WiiVault (1039946) | more than 5 years ago | (#26181969)

Perhaps this is OT, but I honestly don't know. One thing in my area that is driving me literally ape shit is the new installation of what I assume are energy efficient stop lights (LED?). What kills me is that they are barely visible unless you are looking dead on from the right angle. It reminds me of old passive matrix LCDs. They are simply maddening and they are popping up all over the Minneapolis/St. Paul area. I don't understand what the benefit to lights that no one can see are. They seem quite dangerous. In fact even when looking head on at them they are quite dim, and often hard to make out from a distance. If anybody can tell me what the hell they are and why they are around I would be really stoked.

Re:Are LEDs in those impossible to see stop lights (1)

hack slash (1064002) | more than 5 years ago | (#26182143)

LED traffic lights are popping up here in the UK, too. I have to agree they do not always make a good substitute for the old incandescent bulbs.

Usually with LED traffic lights unless you're looking at them dead-on they don't shine very bright, and when you get in the line of sight of some they're almost blindingly bright even from a long distance away, day or night.

Didn't anyone actually do any real world tests of these things, or at least get some opinions of regular drivers? Unbelievable!

Not enought heat from LED to melt snow (0)

Anonymous Coward | more than 5 years ago | (#26181979)

Im from a city in Canada and we had to replace a bunch of LED lights cause they didn't create enough heat to melt the little bit of snow that blows into them.

Snow (0)

Anonymous Coward | more than 5 years ago | (#26181981)

We just had a snow storm in Portland Oregon and there was a problem with the LED traffic lights not melting the snow, so people couldn't see the lights.

Sodium Vapor vs LED (2, Interesting)

lobiusmoop (305328) | more than 5 years ago | (#26182015)

Personally I'd miss sodium vapor street lights if LED replacements became fashionable. Perhaps it is a romantic notion, but it seems to be that one of the reasons sodium lamps have become so popular is that the orange light they emit is reminiscent of fire, and in colder northern climates their warm glow is comforting to people at some deep instinctual level.

Re:Sodium Vapor vs LED (1)

compro01 (777531) | more than 5 years ago | (#26182199)

LEDs aren't inherently blue light. Using proper LEDs or a proper mix of them, it shouldn't be that much of a task to duplicate that colour.

LED signals in Osaka for 5+ years (pics) (2, Interesting)

B4RSK (626870) | more than 5 years ago | (#26182051)

We've had LED signals here in Osaka for 5+ years how and they work very well. Here are some links (in Japanese) with photos showing what they look like:

Red Light, Green Arrow [jsdi.or.jp]

Pedestrian Crossing [michioakita.jp]

Green, Amber, Red [yahoo.co.jp] (the amber is actually brighter than it seems in this photo)

I haven't experienced any problems with them and I drive daily here. There is no noticeable flicker and they are a lot brighter than the traditional signals they replaced.

Crosswalk Sign Problems (1)

JakFrost (139885) | more than 5 years ago | (#26182059)

I just hope that they invest in better LED technology and higher quality control standards than when NYC rolled out the LED based crosswalk signs for pedestrians, the ones with the orange hand and white walking figure.

Throughout the city you can see quite a few of these signs failing in sometimes very spectacular fashion, such as displaying both the hand and the walker at the same time blinking or solid. Other times multiple LEDs have become non-functional and the patterns have changed to comical designs with various fingers missing from the stop hand or body parts missing from the walking figure. I've seen tons of these broken signs but still I'm missing that elusive middle-finger gesture.

One thing that the city did very well is the progressive upgrade of the intersection lights (red, yellow, green) to LEDs. The started off with changing out only the green lights and after the change you noticed right away the super bright new green light at the intersection. At certain times of the evening the new green LEDs are so bright that is almost hurts to look at them directly, but I don't know if this is a physical thing with the human eve being more sensitive to green or with power fluctuations at that time of the day.

After the green light change they changed out the red lights and lastly they did the yellow lights. Since the changes I've seen a number of intersection lights be burnt out or non-functional and I have called them into the new consolidated city wide services line at phone number 311 and the city came and replaced them in a day or two. The failure rate for the intersection lights is a lot lower than for the crosswalk signs, and that's a great thing since the city has many more crazy dangerous drivers than insane pedestrians as it is.

Let's hope the use high quality LEDs and electronics in these new street lights.

if you would like to write fortunes for slashdot (0)

Anonymous Coward | more than 5 years ago | (#26182089)

A reverend wanted to telephone another reverend. He told the operator, "This is a parson to parson call."

all you need is a crayon.

According to the DoE... (2, Informative)

harlequinade (1122273) | more than 5 years ago | (#26182113)

...if every home in the US replaced their five most-used bulbs with CFL's, the energy and greenhouse gas savings would equal taking 8-million cars off the road. The numbers from replacing every street light in a city of 9m people could be just overwhelming. So let's do it nationwide. Now!

Go Inventors! (0)

Anonymous Coward | more than 5 years ago | (#26182123)

1.175 million dollars to figure out how to make street lamps work with LEDs? Maybe if I had the same government connections I could get a nice cushion too... If the DOE R&D is anything like the rest of the American Government, it's spent on vapor, and probably unaccounted for just like the rest of the spent tax-payers money spent on things that don't exist.

Well on the positive side, atleast LEDs exist... I think...

This is ridiculous (1)

arhar (773548) | more than 5 years ago | (#26182353)

This is just great. In NYC right now, they're cutting the city budget, implementing a whole slew of new taxes (taxing Itunes store purchases?), cutting subway service (while hiking the rates)... and what are they spending the money on? That's right, replacing street lights with LED bulbs. Aren't there a little more important things to worry about/spend money on right now?
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