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Dimmable led drivers?

Discussion in 'LEDs and Optoelectronics' started by primuspaul, Feb 13, 2018.

  1. primuspaul

    primuspaul

    91
    1
    Feb 7, 2018
  2. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    This kind of dimmable LED driver is meant to be used with a classic dimmer/switch combo used to control brightness of lamps. The featiure "dimmable" needs to be mentioned since not every LED driver will work with this kind of dimmer.
    For setting the brightness on the low voltage side via potentiometer or similar typically a technique called PWM is used. You can buy off the shelf modules for that purpose.
     
  3. primuspaul

    primuspaul

    91
    1
    Feb 7, 2018
    What if I want to use the dimming module to permanently dim the LED? Do I need a resistor on live 120VAC wire? Is there a cheap way to do it without generating waste heat?
     
    Last edited: Feb 14, 2018
  4. Bluejets

    Bluejets

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    Oct 5, 2014
    Phase control dimming waste heat would be hardly detectable.
     
  5. Harald Kapp

    Harald Kapp Moderator Moderator

    8,830
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    Nov 17, 2011
    A resistor is a cheap way to generate as much waste heat as possible.
    Use one of the PWM modules I linked.
     
  6. Sunnysky

    Sunnysky

    457
    110
    Jul 15, 2016
    This LED driver is NOT meant to be dimmable without issues. It provides a CC output of 300mA +/-3% with TOO WIDE an input range for triac dimming to be practical. max/min =265Vac / 85Vac is 3.4x ratio so the output will track and stay constant over this RMS voltage ratio. So when you want to dim it with an input < 85V it will start saturating the buck coil with more current and it will start making noises (buzz) try to put out max current with low input voltage. Remember it was design to put out constant current,. SO bad choice for a dimmer. upload_2018-3-14_15-47-8.png
     
  7. Bluejets

    Bluejets

    3,104
    608
    Oct 5, 2014
    Note that there are many types of lamp dimmers and most are for a specific purpose and as such most will not work correctly with LED dimmable drivers.
     
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