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    A curious LED lamp...

    I found a LED "sealed beam" 2-terminal floodlight bulb, about 4" diameter, that apparently is 6W at 12V. It's fairly bright, but that's not what was interesting. Looking into the diffuser lens, it didn't have a typical yellowish fluorescent material in it that's typically used for LEDs to make white lamps.

    Odd I thought, but when I powered it up it became apparent what was going on - this lamp is a RGB LED lamp using distinct LEDs! What was weirder...

    At 6V, it lit up red with their lowest Vf.
    Then at ~8V it lit up yellow when the green LEDs turned on.
    Then finally at 10V or so, it's fully white when the blue LEDs turned on with their highest Vf.

    Then going past 12V, it started taking less current as the internal SMPS probably converted voltage to current and reduce current consumption.

    This is the weirdest bulb I've ever seen ... it's a voltmeter in itself much like someone can guess voltage depending on brightness/yellowness of an incandescent bulb. In this case you can tell by looking at the color output.

    I wonder if a lot of these low voltage specialty bulbs are like this now?

    BTW, though it looks like a "sealed beam" I highly doubt it's really sealed and will leak water...
    Last edited by eccerr0r; 11-13-2022, 08:06 PM.

    #2
    Re: A curious LED lamp...

    Is it an automotive type LED or some other type of LED
    9 PC LCD Monitor
    6 LCD Flat Screen TV
    30 Desk Top Switching Power Supply
    10 Battery Charger Switching Power Supply for Power Tool
    6 18v Lithium Battery Power Boards for Tool Battery Packs
    1 XBox 360 Switching Power Supply and M Board
    25 Servo Drives 220/460 3 Phase
    6 De-soldering Station Switching Power Supply 1 Power Supply
    1 Dell Mother Board
    15 Computer Power Supply
    1 HP Printer Supply & Control Board * lighting finished it *


    These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

    1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
    2 Hem Saw Computer Stack Board

    All of these had CAPs POOF
    All of the mosfet that are taken out by bad caps

    Comment


      #3
      Re: A curious LED lamp...

      My guess is that it's for one of those emergency lights when the power goes out.

      Whether this lamp is truly rated for such emergency use is also questionable, though due to the questionable water tightness of the lamp, it may not be good for automotive use.

      Comment


        #4
        Re: A curious LED lamp...

        Hmm. Questionable. I like questionable. I like "let's throw it outside at the mercy of nature and see if it sticks".
        Originally posted by PeteS in CA
        Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
        A working TV? How boring!

        Comment


          #5
          Re: A curious LED lamp...

          Can you post a picture of this device
          9 PC LCD Monitor
          6 LCD Flat Screen TV
          30 Desk Top Switching Power Supply
          10 Battery Charger Switching Power Supply for Power Tool
          6 18v Lithium Battery Power Boards for Tool Battery Packs
          1 XBox 360 Switching Power Supply and M Board
          25 Servo Drives 220/460 3 Phase
          6 De-soldering Station Switching Power Supply 1 Power Supply
          1 Dell Mother Board
          15 Computer Power Supply
          1 HP Printer Supply & Control Board * lighting finished it *


          These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

          1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
          2 Hem Saw Computer Stack Board

          All of these had CAPs POOF
          All of the mosfet that are taken out by bad caps

          Comment

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