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New York City Street Lights To Go LED

Posted by Soulskill on from the big-apple-lite dept.

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."

12 of 303 comments (clear)

  1. flicker crashes by goombah99 · · Score: 4, Interesting

    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.

    --
    Some drink at the fountain of knowledge. Others just gargle.
    1. Re:flicker crashes by digitalunity · · Score: 4, Interesting

      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.

      --
      You can't legislate goodness. Let each to his own destiny, by will of his freely made choices.
    2. Re:flicker crashes by Tokerat · · Score: 3, Interesting
      1. Find a car with LED tail lights.
      2. Look at them as the brake is applied and they illuminate.
      3. "Shake" your eyes left and right rapidly

      You will observe, instead of a smooth trail of light (referred to on film as a "motion blur") like you normally would see, you can see individual "sets" of lights; very broken partial light trails. This effect is exaggerated enough to be realized in this case by the constant movement of your eyes.

      Every set of LED tail lights I've ever seen could produce this effect. How can this be? Apparently, I'm not alone in my experiences, either. I'm certainly not one of those nut jobs who says WiFi makes them nauseous, hell I can't tell teh difference between 320kbps MP3 and WAV.

      I can, however, hear a high pitched whine from an old CRT with no signal, 60Hz monitor refresh gives me a headache, and LED tail lights leave a strobe pattern instead of a smooth trail.

      I believe this is dangerous as it can make determining the point of origin for such types of lights difficult when split-second instinctive brain functions take over. Instead of a line leading to the current position of the tail light, in that slit second my mind has 3 "still frame" snapshots to piece the scene together with - not quite enough information.

      --
      CAn'T CompreHend SARcaSm?
    3. Re:flicker crashes by paul248 · · Score: 3, Interesting

      I've seen a definite flicker in some cars' tail lights as well, so you're not crazy.

      I think the cars pulse the lights at ~50% most of the time, then switch to 100% when the brakes are applied.

    4. Re:flicker crashes by gfilion · · Score: 3, Interesting

      In SoCal, we have LED traffic lights everywhere.

      In Québec we have them pretty much everywhere too. Sometimes when the snow is just the right consistency and falls in the right direction, it sticks to the traffic lights lenses, obscuring them. In the past, the heat generated by the incandescent bulbs would melt the snow, but the new LED lights don't produce enough heat. A city worker has to remove the snow with a kind of small broom attached to a long pole.

      Two steps forward, one step back...

    5. Re:flicker crashes by zenyu · · Score: 4, Interesting

      *sigh* You remind me of the EE graduate student who was showing me and my classmates around his lab one day. To prove the point that humans couldn't hear a 16kHz tone very well he quickly turned the power up from 1 to 11, and through pain practically paralyzed the half of the class that still had their hearing intact.

      Many cars have the flickering tail LED lights, and it has nothing to do with DC-DC converters or other sources of ripple in the supply current. It's simply a matter of the duty cycle timer, the tail lights are "dimmed" not by limiting the current but by turning them completely on and off at a low frequency. The ones I've seen are in the 40-80Hz range, just stick an oscilloscope on there if you don't believe me. The flicker stops when the lights go to full illumination (i.e. the break petal is depressed).

      Now go outside and look at some LED tail lights! Even if you have very poor vision you should be able to see the ones flickering at 40-50 Hz.

      PS If you are legally blind, just don't comment on lighting. You are bound to suffer from foot in mouth at times; go take on those annoying audiophiles buying 1000 euro power chords.

  2. Giant LED light bulbs by pwizard2 · · Score: 3, Interesting

    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.

    --
    "It is a denial of justice not to stretch out a helping hand to the fallen; that is the common right of humanity."
    1. Re:Giant LED light bulbs by Anonymous Coward · · Score: 3, Interesting

      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?

    2. Re:Giant LED light bulbs by dgatwood · · Score: 4, Interesting

      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 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.

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

    3. Re:Giant LED light bulbs by cathector · · Score: 3, Interesting

      > 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.

  3. Bad plan in snowy environment... by Anonymous Coward · · Score: 5, Interesting

    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.

  4. Submitter needs to visit wikipedia. by serviscope_minor · · Score: 3, Interesting

    "We don't need to belabour the advantages of LEDs over traditional lightbulbs"?

    Actually, we do, since we've had lightbulbs other than incandecent for over a decade, and incandecents are never used to light streets. LEDs manage about 100 lumens per watt, similar to high pressure sodium lamps. The old orange low-pressure sodium lamps are still king of the hill at 200 lumens per watt.

    So what were those advantages again? Compared to high-pressure sodium lsmps, they're the same efficiency and lifetime, but a lot more expensive. The only advantage to low pressure lamps is colour, but they loose a factor of 2 on efficiency.

    --
    SJW n. One who posts facts.