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LED lamps vs fluorescent lamps?

Discussion in 'General Electronics Chat' started by Flyback, Sep 8, 2013.

  1. Flyback

    Flyback Well-Known Member

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    A colleague gave this report to me, stating that work on mains powered LED light bulbs is generally a waste of time, do you agree.?..
     

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  2. crutschow

    crutschow Well-Known Member Most Helpful Member

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    I completely disagree. At the present, Leds are still relatively expensive (which will be less so as more of them are used), but their lower use of natural resources (and no mercury), their longer life, and greater efficiency gives them the edge over fluorescents. I have replaced my ceiling recessed lighting fluorescents with LEDs and they give more and whiter light, at about half the power consumption as the compact fluorescents that were replaced (which seemed to have relatively poor lifetime in that application, apparently due to heat build-up in recessed fixtures).
     
    Last edited: Sep 8, 2013
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  3. audioguru

    audioguru Well-Known Member Most Helpful Member

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    My city converted all its traffic lights (they were incandescent) to LEDs a few years ago. You can clearly see the defective LEDs that do not work but the lights have many LEDs that work so it doesn't matter.

    Recently my city converted all its streetlights (they were orange sodium vapour) to white LEDs and the light is good. But some of the streetlights do not work and many are turned on in the daytime.
     
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  4. dave

    Dave New Member

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  5. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Likewise - LED lighting is far superior, except for their far higher cost - but that's balanced somewhat by their much lower running costs.

    And best of all, no buzzing or flickering!!
     
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  6. Flyback

    Flyback Well-Known Member

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    its easy and cheap to make high frequency fluorescent ballasts which alleviate the problem of buzzing and flickering.

    how commonplace do leds have to be before they fall to a reasonable price?.....leds are already used in the absolute billions....almost every television is filled with hundreds of leds

    ok thanks for the comparison, but we'd need details of makes models etc to see if it was a just comparison.......in any case, you say its a "recessed" light, which suggests "downlighting", and indeed the directional property of leds does actually make them preferable for downlighting. so I concede that point to you...however, for general all-room lighting, leds are a poor second to fluorescents.

    this is certainly interesting...though I suspect this is more funded from a government researching inquisitively into led performance, rather than any genuine belief that leds make more efficient streetlights than sodium or induction lamps etc....of course, I appreciate that you were never saying that they were....but this interesting point does emerge from your valuable observation....(ie, im not arguing with you on this point)
     
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  7. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Buzzing yes, flickering - NO!.

    And the endless maintenance of florescent lights drives you mad!!
     
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  8. Flyback

    Flyback Well-Known Member

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    flicker doesn't happen to HF flu's if designed properly.
    By "endless maintenance", I take it you mean you believe they fail more often than led so they need replacing more often?
     
  9. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Tubes still flicker, it's the tube not the ballast.

    Not just 'more often', it's pretty well a continuous job at work replacing tubes or starters (and often complete fittings).
     
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  10. Flyback

    Flyback Well-Known Member

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    ....high frequency electronic ballasts don't have starters......youre talking about the old fashioned 50hz fluorescents....a totally different thing.

    With the HF ballasts, the tubes definitely don't flicker if the ballast is designed properly.
     
    Last edited: Sep 8, 2013
  11. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Ah, that will be because they're connected in parallel :D.
     
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  12. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Traffic lights would NEVER have the LEDs in parallel like cheap Chinese flashlights. Since they operate on mains voltage then the LEDs are probably in series.
    When new all 20 or 30 LEDs light then some fail after a while.
     
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  13. Flyback

    Flyback Well-Known Member

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    so they must be failing short.....that's interesting, LEDs don't usually fail short unless they suffer significant overcurrents.......if leds die from general wear and tear, then they usualy fail open (almost always)........the fact that these leds are failing short points to serious mis-design in the led driver.
     
  14. MrAl

    MrAl Well-Known Member Most Helpful Member

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    Hi,

    I use LED's for almost everything now. I have several LED "bulbs" designed for 120vac mains operation and they work pretty nice and use very little power. They go on sale a lot now too so you can pick one up for about 8 dollars USD.

    What i like about the LED "bulbs" is that they fit in an ordinary lamp socket, so they dont require a specialized fixture just to run them. And because the base is standardized, they fit in any lamp made for an ordinary 120vac incandescent bulb.

    It's interesting what has been said about the aluminum heat sink, and yes that's true, they have a heat sink built around them and it makes them more heavy. It's not too bad though as they work just the same as a bulb for most lamps and you dont notice the heat sink because it's under the hood or shade of the lamp. They are a bit longer though than an ordinary bulb so they might stick out a little from a small desk lamp with hood. Not too much of a problem though. Though I dont think they are made for enclosed box applications like you might find in a shower stall. The heatsink should get air circulation.

    Cant think of anything else offhand except i'd never go back to fluorescent lighting again, ever, even if someone gave me one. They start up funny, and sometimes the bulb burns out too quickly. I had several smaller bulbs give out way too soon so i gave up on those a long time ago. I have one curly bulb in operation now and once that goes that's probably it for my fluor's.

    You can also get 12v LED bulbs that take about 4 watts power but put out much more equivalent light, and they are pretty bright and make nice desk lamps.
     
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  15. Flyback

    Flyback Well-Known Member

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    In the US you are paying $8 for a LED bulb?...that's £5.12 UK.....I cannot understand this, I thought stuff was cheap in USA?......I pay about £2.00 for CFL bulbs in UK. They must last a long time as I hardly ever have to buy them for replacement. LED bulbs with bayonet fittings in UK cost about £13 (and thats for 6W = same as 60W incandescent) . £13 is a ridiculous price for a light bulb.
     
  16. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Some LED light bulbs are Name Brand like Philips and are certified to be safe in your country.
    Other LED light bulbs are Chinese and are NOT certified to be safe. If it sets your house on fire then the insurance company will laugh and not pay for the damage.

    Most light bulbs in my home are Name Brand compact fluorescent that work well for many years. They are inexpensive when on sale.
    My electrical utility company gave away compact fluorescent light bulbs FOR FREE. They were all recalled when they learned that the certification label was stolen and the bulbs were NOT certified to be safe. Some of them dripped flaming plastic underneath them.
     
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  17. MrAl

    MrAl Well-Known Member Most Helpful Member

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    Hi,

    Yeah but the cost is spread out over time. I'll probably never have to buy another one now unless i want a brighter one (the ones i have now are equiv to 75 watts incan).

    But maybe the real advantage is the nature of the light output itself. It's almost pure white so colors render perfectly. You can get warm whites, but i recommend the cool whites as they render colors better.

    Also, the base doesnt get super hot like those curly things.

    Long long time ago i welcomed cool white fluorescent lamps but now that LED's are here i dont like them anymore and go with LED's. I used to like fluorescent because it renders colors much better than incandescent. But now the LED's do that even better and with less fuss.

    Another thing to watch out for with the curly bulbs is that they can become brittle over time. Then you go to remove one from an overhead lamp and it breaks in your hands. Have to be careful about that.

    I also run low voltage LED's now and then that operate off of around 5v. I built those myself long before the regular LED bulbs came out.

    I guess you could say that LED's are my favorite form of lighting, and i dont see that changing especially since they just keep getting better.

    Yes, 8 dollars for a bulb, and i'll never have to buy another one for those lamps ever again. So 8 dollars over 10 years if im still around and that's about 80 cents per year. Compared to my other bills that's below the noise floor.
     
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  18. lipschutz

    lipschutz Member

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    60W incandescent bulb doesn't mean 60W equivalent light energy, i would be surprised if it is more than 10% of the power rating.
     
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  19. crutschow

    crutschow Well-Known Member Most Helpful Member

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    Don't have a crystal ball to for LED price drop, but I know the LED prices have come down significantly in the past few years and I expect in a few more they will be approaching the prices of CFLs.

    I replaced my 16W CFL floodlights with 11W LED floodlights. Even though they are rated at the same lumens the LED is noticeable brighter and the light is a more pleasing white color.

    And why is that? We need more details to see if that's a justifiable statement. :rolleyes:
     
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  20. Flyback

    Flyback Well-Known Member

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    @Crutschow, Your example shows a led downlight (11w one), so yes, LEDs are brighter as downlights than flu's.

    Regarding the comparison between led and CFL......having heard you guys out, maybe the little curly CFLs are less efficient than the leds(?).......but id be surprised if a led bulb hanging in the middle of the room illuminated the edges of the room as well as a CFL (curly bulb).

    regarding office lighting and industrial lighting, the prevalence of fluorescent tubes shows you what is more efficient and cheaper......they wouldn't use them if leds were cheaper or more efficient................think Tesco's supermarket in UK.....Tesco scrimps and scavenges after every single penny......and Tesco use flu tubes......so you can bet flu tubes are overall cheaper than led.
    I hear 100lm/w for flu and on average ~65lm/w for leds.
     
  21. dr pepper

    dr pepper Well-Known Member

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    If you look at a 6v 3w incadescent bulb, then a 3w led that basically and literally shows you which way we are going.
    Nearly all pocket torches are led, new street lights are led, they are even fitting them in vehicles.
    Not a waste of time.
     
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