Cheapo 12v dimmer question

Discussion in 'The Projects Forum' started by majhi, Jan 11, 2015.

  1. majhi

    Thread Starter Member

    Jul 2, 2014
    49
    1
    So I, being a cheapskate, bought a little 12v dimmer switch kit on eBay from China (http://www.ebay.com/itm/221457310367). Currently using it to dim an LED strip. I put it together and some connection somewhere between J1 and the rest of it isn't functioning, but I can bypass some of the components and get it working for testing purposes. So my question concerns the pot. When I turn the pot, I can get up to full brightness and to nearly-off, but not really in between. I can turn it up to about 20% brightness, but if I turn it any more, it jumps up to 100%.

    Is this something that a new pot can fix? Or do I need to just start over?

    (Sidenote: This is just in-line, correct? Or do I need to connect both a positive and negative wire somewhere?)
     
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,281
    1,227
    It is an AC dimmer not a 12 volt dimmer.
     
  3. majhi

    Thread Starter Member

    Jul 2, 2014
    49
    1
    Doh! I feel like an idiot now.
     
  4. majhi

    Thread Starter Member

    Jul 2, 2014
    49
    1
    Regardless though, why is the pot behaving this way?
     
  5. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,281
    1,227
    I would expect it to just turn on once the pot was turned up a bit and stay on unless the current for the diodes isn't high enough to "latch up" the triac.
     
  6. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
    463
    Listing :
    PCB x1 piece
    WH149-500k with switch potentiometer x1
    potentiometer cap x1
    DB3 bidirectional diode x1
    2k resistance 0.25W x1
    MAC97A6 x1
    104 630V CBB capacitance x1
     
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