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Thread: LEDs. What gives?

  1. #21
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    Quote Originally Posted by glitch View Post
    You can get LED replacements for bayonet and wedge base signal lamps at most auto stores.
    Auto stores mark up LED replacement bulbs like 1000%, paying $20-40 for what you an get directly from China for $2-3 doesn't make sense.

    Quote Originally Posted by glitch View Post
    they're about the same brightness, but much less power consumption -- a good thing for the tired old VW wiring harness!
    The power consumption of an automotive LED bulb vs an incandescent is going to be roughly the same. The reason for this is that many cars have circuitry to detect dead bulbs, and if the current draw is too low, it will think the bulb is dead and trigger some fault condition. My 1988 Dakota can detect burned out blinker bulbs and will keep whichever side solid on instead of pulsing if a bulb is out.

    The way that an LED replacement bulb defeats the dead bulb detection is by using some high power resistors, which is not an ideal solution because it generates lots of heat. While an incandescent bulb is fine running at hundreds of degrees all day, an LED will suffer thermal death if run too hot for too long. LED bulbs can get smokin' hot, especially those crappy "corn cob" style which cram as many 5050 LEDs into as small as space as possible.

  2. #22
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    It depends--many auto LED replacement vendors sell a shunt resistor kit, but not all applications require them--and some dead-bulb detectors will work with either LED or incandescent lamps.

  3. #23
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    I have input in response to a few things in this thread-

    1. I hate LED tail lights, especially when they charge an arm and a leg for an assembly with $5 worth of LED's in it.
    2. I hate LED street lights. They replaced the mercury vapor light outside my house with one, and it's like having a sun shining into our house at night.
    3. I hate newer Camry's lack of rear view. The reason they always have those dents is because you can't see shit out the back of anything 1992ish onwards.
    4. Over here in Australia, Telstra (our main phone carrier) mandated that all their vehicles have the headlights running permanently as a safety measure. You can now tell a Telstra vehicle from a mile away because it will almost always have one headlight out.

    End rant lol!
    Bobby.

    (Looking for Olivetti M24/AT&T 6300 Keyboard - but I'm in AUS!)

  4. #24
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    What I don't understand is why so many cars have burnt out LED lights, but the LED lights on my 30 year old floppy drive works just fine. I thought LEDs were not supposed to burn out.

  5. #25
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    Quote Originally Posted by vwestlife View Post
    That's almost as common as the Camry Dent.

    http://jalopnik.com/the-incredible-m...ent-1785413530

    Regarding that image, its plastic. Its so easy to pup it out back into shape. Car owner is just lazy.

  6. #26
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    For the LED tail lights, are you talking about like the entire tail light, plastic and all? Those are somewhat expensive to make due to the injection molding, but they could be priced lower. For the COB LED bulbs that they sell at auto parts stores, yeah those are like 1000% profit margin items. You can generally get the same COB bulbs directly from China for a lot less, though I wouldn't recommend them.

    I don't like LED tail lights on newer vehicles because they flicker like crazy. I don't know if they're being PWM driven or driven from an AC source, but the frequency is low enough that it's distracting, especially at night. I don't know why they don't drive them from a straight regulated DC source, maybe it's for reliability or something.

  7. #27
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    Quote Originally Posted by flashedbios2012 View Post
    What I don't understand is why so many cars have burnt out LED lights, but the LED lights on my 30 year old floppy drive works just fine. I thought LEDs were not supposed to burn out.
    The LED in your floppy drive sees intermittent use at a low operating voltage which means it will pretty much last forever whereas an LED Headlamp is using still relatively new high output white LED's on a chinese ballast running a higher operating voltage.

    The formula is !product(cost+china)
    = Excellent space heater

  8. #28

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    One of the problems I see REPEATEDLY in high brightness LED implementations is the lack of a pull-down resistor to stop them from burning out when power is first applied. You see this in everything from dollar store flashlights to taillights and street lights.

    It's an essential part of the circuit the moment you deal with any LED that takes more than a volt, and cheap ass buggers are skipping it to save a penny... well, and planned failure to make you spend more money.
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  9. #29
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    I'm not sure what you mean by a "pull down resistor'. To me, this is terminating a transmission or signal line with a resistance to ground.

    Do you perhaps mean a "current limiter" or "ballast"?

  10. #30

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    I find it slightly interesting just how pervasive the notion; "made in china means it's shit quality", completely pervades all aspects of our life. The whole country's reputation is complete garbage.

    Then I see reputable companies try to compete to stay in business, only to fall in the same trap.

    sad.
    It is a mistake to think you can solve any major problems just with potatoes.

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