Help Selecting Potentiometer For Strip LED Lighting Dimming Control

Discussion in 'General Electronics Chat' started by MaxArk68, Jul 11, 2018.

  1. MaxArk68

    Thread Starter New Member

    Jul 11, 2018
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    I am a beginner in electronics, and much of my limited knowledge is based on high school electric classes (30+ years ago) and some self study online. I'm struggling with understanding potentiometers. Much of what I read is over my head despite my efforts to carefully digest what I found.

    My project is simple. (I hope).

    I have a series (7) of clustered LED strips. (each cluster consistes of two strips of 10 LEDs each connected in series ... 20 LEDs.) The clusters congregate at terminal block which feeding the 140 LEDs by a 12V, 2A, 24W power supply.

    I would simply like to add a potentiometer to the circuit (before the terminal block?) to be able to dim all the clusters simultaneously. To avoid blowing my components up, or myself, I can't get a handle on the specifications of the potentiometer I need. There seems to be a lot to consider, and I'm not sure what are the critical specs to consider.

    Would someone be able to assist me in finding an appropriate pot based on the intended use and componets?

    Power supply - 12V Class 2 2A, 24W
    These are the specs for the LED strips

    Thank you all in advance for your patience and assistance.
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    The leds will have series resistors and this controls the brightness of each led not the voltage. The leds will be wired in Parallel.! !
     
  3. whitehaired novice

    Member

    Jul 15, 2017
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    Surely the same manufacturer sells a dimmer. If not, others do--made for exactly that purpose.
     
  4. MaxArk68

    Thread Starter New Member

    Jul 11, 2018
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    Thank you for your replies ...

    These are strips of LED's, and yes they have resistors built into the strip . I'm not looking to dim each individual LED, but the entire strip (or cluster of strips).

    This is a project, and the materials are not sold specific to any particular lighting purpose. The manufacturer sell the connectors for the strip leads, but not a dimmer. It appears I have to provide my own method of dimming for my project board.
     
  5. whitehaired novice

    Member

    Jul 15, 2017
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    Google LED dimmer--I say one for $4 + shipping
     
  6. MaxArk68

    Thread Starter New Member

    Jul 11, 2018
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    Thank you whitehaired novice ... these I don't quite think is what I can use. I can't integrate them into my project.

    I am trying to replicate cockpit backlighting for a home cockpit simulator. The dimmer control has to be customized to match that of the cockpit. It needs to be mounted from behind panel and have a turning range of 0 (off) to 280 degrees rotation (full intensity).

    There are 7 panels, each backlit by 2 strips of ribbon LED. These are all dimmed simultaneously from a knob (potentiometer?) on the cockpit panel.
     
  7. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    JWHassler likes this.
  8. MaxArk68

    Thread Starter New Member

    Jul 11, 2018
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    Ahhh ... I see. Thanks for that little extra tidbit to help me understand why a potentiometer alone isn't what I need either.
    I would imagine I could take the casing off this and use the components in my project as necessary.

    I assume this would do the same with the ability to handle more LEDs should I wish to expand my lighting?

    Thank you!!!
     
  9. olphart

    Active Member

    Sep 22, 2012
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    That Amazon unit looks good, but read the reviews. The current handling may be vastly overrated, a common practice.
    Only way to know is buy one, open it up and spec the MOSFET. You also can swap the FET for higher capacity and/or a heatsink.
    I've done that on several units, works well.
     
  10. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    yes that can handle more (supposedly) and yes you can remove the case if needed..

    Thanks to olphart for the reminder to you that with MANY um...."Chinese" products (I think thats just about everything now).. The specs are often overstated/incorrect,etc.. so one should always use caution when attempting to push anything to the limit..
    I would likely derate everything by 50%
    Many times they are simply copying a reputable product and subbing out inferior/low cost components/materials,etc... which has an effect on the specs..
    And they don't give a crap if your house burns down or whatever.. Once the product has left the factory their part ends there..
    Its the world we have become when cost is the only driving factor..
     
  11. olphart

    Active Member

    Sep 22, 2012
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    Tnx & doff of my cap to mcgyvr... I've found the Asian sourced objects to be Great driver devices.
    BUT, "trust but verify" power capacities.
    It's fairly easy to respec the MOSFET based on the original part number, just step up the ratings.
    Don't forget heatsinking is BIG, and be certain gate voltage levels match (logic etc)
    I've swapped out a small FET for a Beefy on a cheap RF based unit several times, way good.
    A shame the RF units are all same channel (as far as I know...).
    So I have to advise client: pick RF for coverage, use IR for directive (which I build).
    I can't find IR based PWM controllers (what up with that?).
    They could make one for ~$2-3, where I can't do it for <$10.
    Am I missing something ?? Good Hunting... <<<)))
     
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