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Other LEDs light bulbs drop in price 10x thanks to new discovery

Discussion in 'General' started by Veles, 31 Jan 2009.

  1. Veles

    Veles DUR HUR

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    Although TBH, £20 for a bulb that will last you 60 years and take up 1/3 of the energy as an energy saving one is still not a bad price, but now we will be able to get 'em cheaper, as well as other LED based stuff. I was wondering why we weren't using LEDs as lightbulbs in our houses yet.

    EDIT: Full story
     
    Last edited: 3 Feb 2009
  2. chrisb2e9

    chrisb2e9 Dont do that...

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    people aren't good at looking at long term prices. they see 20 for a lightbulb and think they can get something that does the same job for 1 dollar. never mind that they need to buy another one every year for life and it will cost more in power...
     
  3. DougEdey

    DougEdey I pwn all your storage

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    This is old news, they've been used for ages in bars & clubs as main lighting source.
     
  4. capnPedro

    capnPedro Hacker. Maker. Engineer.

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    Some people complain about the light they give out not being in the 'natural spectrum' or something.
     
  5. Jipa

    Jipa Avoiding the "I guess.." since 2004

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    It's always a gamble getting LED lights for such use.. They do cost quite a bit and if either the color temperature or output isn't what you expected, you aren't gonna buy another LED bulb for a long time.

    Being a geek myself I love leds and have a DIY-led-light setup in use. I also don't mind the blue-ish color of the light, but also can see how that puts some people off. Not all leds lamps have the nasty tint, but it's still what people are afraid of, I thinl.
     
  6. Smilodon

    Smilodon The Antagonist

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    Warm-white LEDs are becoming more and more common making them a pretty good replacement for incandescent sources.


    Some of the problem with LEDs though is light output and the ability to use them with most dimmers.

    Some bulbs also have the strange tendency to put out a very yellow glow in the center, and a blueish white light around the edge of the beam. This has gotten better in le last couple of years, though.

    Personally I still prefer incandescent bulbs because the light doesn't have ANY flicker to it, and they give a warmer color when dimmed, making the light feel warmer, and more comfortable to the eye. (It's easier to see in dim orange light than dim yellow light)
     
  7. steveo_mcg

    steveo_mcg New Member

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    Yeah, i'm not convinced. They would have to work for a long time to make up for that expenditure, lets face it, its not just one bulb you'd kit out a few rooms with them. If a fault developed with the ring main and blew them out its an awful lot of money to replace them, i have one room which killed an energy saver in a few weeks because there is some thing wrong with the fitting or switch but old incandescent bulbs last around there normal life span.

    Short story: They would have to live to around there estimated life expectancy to make it worth while which is all well and good barring faults.

    Edit: just reread the quote, so they should be getting cheaper... hmm, if they are warm then i might be interested the normal led is just too harsh as a main light.
     
  8. profqwerty

    profqwerty New Member

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    Now when people move house they'll take the light bulbs too.
    They flicker as well, at 25Hz instead of 50 so I guess that can give people head aches. (One half turn on on the the 0-180 degree wave, and the other half are on 180-360 degrees)
     
  9. Smilodon

    Smilodon The Antagonist

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    If they have a full rectifier bridge they will flicker at 100Hz, actually. 50Hz if they have a half bridge. (The led will glow once 0-180deg. side of the sine and once on the 180-360deg. side when using full bridge.)
     
  10. BUFF

    BUFF New Member

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  11. ozstrike

    ozstrike yip yip yip yip

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    I have LED bulbs in my bathroom. I was just trying them out because I saw them for sale in B&Q. Only problem is, they aren't as bright as I'd like, but I did decide to buy the blue ones rather than the white ones.
     
  12. pistol_pete

    pistol_pete Air Cooled Fool

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    I'd love LED bulbs, the problem is my flat has no less than 24 of the nasty hallogen spotlights in the ceiling, so replacing them with LEDs would never be affordable. We mostly use fluorescent lamps instead. I'm looking forward to incandescent bulbs being banned for sale from 2012.
     
  13. Silver51

    Silver51 I cast flare!

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  14. Sp!

    Sp! Well-Known Member

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    Most LED lights can't be dimmed either, making them useless in a lot of applications...
     
  15. woof82

    woof82 New Member

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    Could just install a 12v DC lighting rail and save yourself a hell of a lot of money instead of having a transformer/rectifier in every single light socket.

    You can buy different colour "temperature" LEDs, they just put different amounts of flourescent elements in the LED which absorbs some of the blue and re-emits it at longer wavelengths.
     
  16. notatoad

    notatoad pretty fing wonderful

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    incandescent bulbs (or any bulbs connected directly to AC) have some flicker. it might not be naturally noticable but it is there. to see it for yourself, find a light at the end of a long-ish cord and swing it in a circle while it is turned on. you will see a circle of light with a small gap where the light flickers.

    LEDs actually do have no flicker, as long as they are connected to a proper DC power source.
     
  17. Smilodon

    Smilodon The Antagonist

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    the problem with a 12V rail is that it will need a whole new network of cables. It's all good in a new house, but not in existing installations.


    All white LEDs do this. They are really UV LEDs with phosphor in the die. White leds do come in lots of different color temperatures, but the phosphor coating is often uneven, making the emitted color uneven.

    edit:


    The thing is that incandescent bulbs are much slower since the coil in the bulb is able to keep up the temperature (and the emitted light) between each phase of the sine wave. The coil can in some cases glow for several hundreds milliseconds after it have lost power. LEDs and CCFLs stops emitting light pretty much instantaneously when connected to a AC source (Which we are talking about here).

    A DC source is another thing, but very few houses have a proper DC source. The norm when it come to LED replacement bulbs is having the transformer inside the bulb, meaning that the transformers have to be very compact. Often this consists of a rectifier bridge and a resistor. I still haven't seen one with some caps to smooth the current.
     
    Last edited: 31 Jan 2009
  18. Herbicide

    Herbicide Lurktacular

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    You've not heard of Pulse-Width Modulation then?
     
    Last edited: 31 Jan 2009
  19. DXR_13KE

    DXR_13KE BananaModder

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    [citation needed]
     
  20. capnPedro

    capnPedro Hacker. Maker. Engineer.

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    Aren't most dimmer switches just potential dividers? Not PWM...
     

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