Help with dc polarity inversion

Discussion in 'General Electronics Chat' started by jscipio, Feb 19, 2010.

  1. jscipio

    Thread Starter New Member

    Feb 19, 2010
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    0
    I have been trying to install lighting in my model rail passenger cars. So far the concept works using LED's, however only in one direction. I know when changing the direction of the current the LED will blow. What component(s) must I install so that when reversing the current the LED will continue to function. Thanks!
     
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
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    Two possibilities I see. One way is anti-parallel each LED with another LED. One will light with each polarity. The other is add a bridge rectifier (or 4 diodes)...the car supply from ~ to ~, with the LED and resistor between + to -.

    Ken
     
    Last edited: Feb 19, 2010
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    You can use a diode bridge http://en.wikipedia.org/wiki/Diode_bridge. Connect your "unknown" polarity voltage to the AC voltage input Marked with ~. A diode bridge can be built by separate diodes or purchased as a component.
     
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