5 pin dual-gang pot (former walkman volume control) as LED dimmer?

Discussion in 'The Projects Forum' started by heimerdinger, Jan 20, 2016.

  1. heimerdinger

    Thread Starter New Member

    Jan 20, 2016
    2
    0
    Hi AAC,

    I am just getting into electronics etc and this is my first project, so please forgive me if I'm horribly ignorant here.

    I've assembled a circular light attachment for my camera for Macro photography (battery + 8x(LED + resistor) in parallel). Works great with the exception of a fried LED, but that can be taken care of.

    What I would like is a way to easily adjust the brightness of the LEDs. I've taken the volume dial out of an old sony walkman and according to google it appears to be a 5-pin dual gang pot ("C103" on the underside). Will this work as a dimmer for the LEDs, and if so can someone help me understand the wiring required to make it happen? I have looked (and will continue to look) for instructions on wiring 5-pin pots but I'm not having much luck.

    Alternately if this will not work, is there something that will?

    Many thanks for any assistance anyone can provide.

    - Heimerdinger
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,813
    1,105
    Welcome to AAC!
    The 103 marking indicates that each pot has a resistance of 10 thousand Ohms. Quite unsuitable for use on its own as a dimmer control. However, it could be used in conjunction with other components. How much current does each LED draw, and what is the battery spec?
     
  3. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,003
    745
    What voltage are you running them on?, a normal red led takes approx 10-20mA, which is usually a 330 to 1k resistor on a 5 to 15V supply.
     
  4. heimerdinger

    Thread Starter New Member

    Jan 20, 2016
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    0
    Hi Alec,

    To simplify things (for myself) but complicate this thread, I actually found a 3-pin pot which I believe had been used to tune picture focus on a rear projection TV (which I may or may not have torn apart for the Fresnel lens... muahahahahahaha!).

    So that's what I attached to the ring light and incorporated into my circuit. ATM I simply have it connected via 2 of the pins in series on the way to the power (9V battery is what I had handy). I assume the 3rd pin is ground, please correct if I'm wrong.

    There is ~340 degree range to spin the knob but only a small fraction of that allows the LEDs to light up and the dimming is extremely finicky. Looks to me like it's too strong of a resistor. Is there any way to spread that resistance out so I have more control over it?

    To answer your question, I'm not sure of the current draw but they are 8 white LEDs, each with an 82 ohm resistor.

    Please forgive my ignorance, I am totally new to this.
    Much to learn, I still have.

    - Heimerdinger
     
  5. DickCappels

    Moderator

    Aug 21, 2008
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    Alec_t likes this.
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