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New LEDs cheaper and more efficient.

Discussion in 'Environmental Discussion' started by Godiva, Aug 21, 2008.

  1. Godiva

    Godiva AmeriKan Citizen

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    New LEDs cheaper and more efficient than CFLs.

    The incandescent lightbulb that wastes 90% of the electricity as heat is dying, we all know that. But a new breakthrough in solid state lighting might also kill compact fluorescent lightbulbs (CFLs) faster than some expected. Scientists at Purdue University have figured out how to manufacture LED solid-state lights on regular metal-coated silicon wafers (more details below). What this means is: much lower costs.
     
  2. Tideland Prius

    Tideland Prius Moderator of the North
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  3. dwreed3rd

    dwreed3rd New Member

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    I hope the LED will be dimmable. I've switched out most of my incacesents for CFL's but there's still a few place I use them. I have all but a couple of our cieling lights on dimmers and the CFL's do not work with dimmers. The other places are foyers, staitways, garage door openers, areas where by the time it takes to warm/brighten up you're out of there. I've mixed CFL's with incadecents in the vanities and bathrooms. The gives us some instant light while the CFL's brighten up for the more lumen requirements. And don't forget to recycle the CFL's. I can't believe how many people that I talk to love the CFL's but have no idea that they contain mercury. Go figure. :decision:
     
  4. ceric

    ceric New Member

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    Heat generated (though much less) is still a major killer for LEDs.
    High-power single-unit LEDs is still expensive because of that issue. I believe Audi is the 1st company to employ LED headlights on their vehicle.

    Also that LEDs needs voltage regulator (small PCB board or a single chip to maintain voltage within certain range) which can be found inside every LED torch. To a certain degree, LED lights are "dimmable", but not as flexible as incandescent bulbs, certainly better than the CFLs.
     
  5. nerfer

    nerfer A young senior member

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    From the article:
    The new techniques yield a crystalline structure aligned to the crystalline silicon. This means that the LEDs are less prone to defects and will perform more efficiently [...] silicon dissipates heat more effectively than sapphires. This will reduce damage during operation and lead to longer lifetimes and more reliability..​

    I'm still waiting for darell's input on this.
     
  6. Tchou

    Tchou Member

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    Nope, they only use Leds as Daytime running lights on some models... Audi R8 can have it as full headlights as an option..
    But Lexus (Toyota) was the first to use it on the LS 600h (the high en Lexus Hybrid version...)
     
  7. boulder_bum

    boulder_bum Senior Member

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    From what I understand, all LED's are dimmable.

    What I hope is that they'll be sufficiently bright! I have a couple of LED bulbs at my house that I use to light the front porch/garage overnight. They work well there, but the light output is much too dim for indoors. I've heard complaints that even the 80-LED monster bulbs still don't put off that much light.

    Good news in the OP, though! I'd love to go LED anywhere I can! They make CFL's look like energy hogs and they last longer.
     
  8. Tchou

    Tchou Member

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    All leds are dimmable, Light emission from a led is very difuse so you get the impression of little light emission, but with the last generation Leds you will have plenty of power...

    Some flashlights use only one Led but the fact that the light source is ponctual makes it use the reflector on an optimal way, and this is quite more efficient than a standard lightbulb...
     
  9. Sufferin' Prius Envy

    Sufferin' Prius Envy Platinum Member

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    I have two dimmable CFLs, one in the living room ceiling and one for the front porch light.
    The reason I use a dimmable CFL for the porch light is it is being regulated by a photo sensor to turn it on and off. Regular CFLs can burn out quickly with a photo sensor.

    I also have two 3-way CFLs and also a 'full spectrum' CFL in my office room.

    I have been using all of these CFLs for the past three years.

    Dimmable Reflectors, Dimmable Torpedo, Dimmable Candle Bulbs
     
  10. dwreed3rd

    dwreed3rd New Member

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    Gee! Thanks! I guess it's been that long since I checked bought mine. I bought enough to swap out the ones I wanted to replace and saved the incadecents to reuse as they burn out. I'll have to make a trip to Home Depot this weekend. I can't believe it haven't noticed them. :embarassed: Thanks again.
     
  11. KK6PD

    KK6PD _ . _ . / _ _ . _

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    Actually LEDS are CURRENT driven devices. The regulator you speak of limits the current supplied to the led to prevent thermal runaway and thus blowing out the led.
    Leds are dimmed by a process called PWM, or Pulse Width Modulation. Its a square wave that the square wave pulse width is varied thus achieving a smooth dimming effect.
    The big problems with LEDS is that they just are not putting out enough Lumens of light. The specs are getting better, but they still need to be brighter. A good heat sinking system will take care of the heat issues.

    Soon, be patient, it will happen!!

    73 de Pat KK6PD
     
  12. dwreed3rd

    dwreed3rd New Member

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    WWait a minute. Does this mean I can or cannot use the existing 8-10 existing wall dimmer switches with the dimmable CFL's?
     
  13. KK6PD

    KK6PD _ . _ . / _ _ . _

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    LEDS are NOT CFL's!!! Apples and Oranges.

    If you have a special dimmer that will work with a CFL, great, use it. But do not try to dim a LED with it!!! You can vary voltage to dim a led, but you get much better response with a PWM system!

    73 d Pat KK6PD
     
  14. dwreed3rd

    dwreed3rd New Member

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    I'm sorry. My brain was still stuck on some previous posts re: my Q's on CFL's. I had not been aware the they came out with a dimmable CFL and wondered if they would work with my existing dimmer switches. I do understand the difference. Planning to replace the bulbs in the Avalon with LED's as they expire, pairs where applicable, of course. Thanks again for the clarification.