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Chinese lumen lies

  • sheepish Top 10 Forum Poster Tuesday, January 10, 2017 12:44 PM Reply

    Brightness: 800 lumens


    Theoretical Lumens    200 lumens    

    Actual Lumens    120 lumens    


    Which lie do you expect us to believe this time, DX?

    DX has found a new way to deceive customers:
    Use reviews for different products that have not been bought
    by the person who wrote the review.
    http://club.dx.com/forums/forums.dx/threadid.1462252
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  • desolder Top 10 Forum Poster Wednesday, January 11, 2017 8:28 AM Reply

    An LR41 cell has about 25mAh. With the claimed 3 hour runtime, this averages to 8.3mA. Assuming an average of 1.25V per cell, this equal an average power of 31mW. Assuming 100lm per watt (being geneorus here!), means 3.1 lumens. That's in the right ballpark for these cheap single 5mm white LEDs.



    But it sure looks pretty...

    What's up with the scrubbed LED driver IC markings?
    What are they trying to hide?

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  • gasbag11 Top 10 Forum Poster Wednesday, January 11, 2017 10:24 AM Reply

    Assuming 100lm per watt (being geneorus here!), means 3.1 lumens. That's in the right ballpark for these cheap single 5mm white LEDs.


    But... but... it says; Emitter Brand    Cree.   lol


    ALWAYS ask questions about a specific item on its
    page. Scroll down and click on "Post a new topic".
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  • sheepish Top 10 Forum Poster Wednesday, January 11, 2017 7:38 PM Reply

    Powered by: 3 x LR44 batteries(included)


    My website says 110-150 mAh. That could work out to a whole 50 mA! From a Cree XP-E, R2 bin, that would be about 18 lm.


    I have a keyring torch I modified to run a Cree XR-E with TIR optic directly from 4 x LR44 cells with no resistor. With fresh cells it draws about 350 mA and quickly goes downhill from there. It still provides useful illumination while drawing well under 10 mA.

    DX has found a new way to deceive customers:
    Use reviews for different products that have not been bought
    by the person who wrote the review.
    http://club.dx.com/forums/forums.dx/threadid.1462252
    Posts(23348) | Reviews | Tip post

  • gasbag11 Top 10 Forum Poster Wednesday, January 11, 2017 10:30 PM Reply

    Surely it's at least 120 lm. Just look at the photo. 



    And we all know there's no way to make a light look brighter than it actually is.  

    ALWAYS ask questions about a specific item on its
    page. Scroll down and click on "Post a new topic".
    Posts(11373) | Reviews | Tip post

  • desolder Top 10 Forum Poster Thursday, January 12, 2017 1:46 AM Reply

    Power Supply    3 x LR41    


    I guess it takes both LR44 and LR41? LR44 would be the preferred choice since it's the larger cell.

    What's up with the scrubbed LED driver IC markings?
    What are they trying to hide?

    Posts(6967) | Reviews | Tip post

  • sheepish Top 10 Forum Poster Thursday, January 12, 2017 6:37 AM Reply

    Brightness: 800 lumens

    Theoretical Lumens    200 lumens    

    Actual Lumens    120 lumens   


    Powered by: 3 x LR44 batteries(included)

    Power Supply    3 x LR41    

    Voltage    1.5   


    Another DX classic product.

    DX has found a new way to deceive customers:
    Use reviews for different products that have not been bought
    by the person who wrote the review.
    http://club.dx.com/forums/forums.dx/threadid.1462252
    Posts(23348) | Reviews | Tip post

    post edited by sheepish on 1/12/2017 at 6:40 AM
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