Wiring leds to run forward or backward

Discussion in 'The Projects Forum' started by Holder350, Mar 4, 2010.

  1. Holder350

    Thread Starter New Member

    Jan 17, 2010
    7
    0
    Can this be done?? I am wiring a system that constant burns and flashes a light, and depending on settings power comes from either wire...

    So, is there a way to do it, or am I stuck running an incandescent?

    12v System btw
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    You can use a full-wave bridge, or two LEDs back-to-back.

    With the full-wave bridge, you can use a cap to keep the supply voltage more constant.

    Either way, you will need to use a regulated current supply or resistors to keep the current through the LEDs under control.

    How many LEDs were you planning on driving? And what are their specifications?
     
    Last edited: Mar 4, 2010
    Holder350 likes this.
  3. Holder350

    Thread Starter New Member

    Jan 17, 2010
    7
    0
    Just driving one....Actually a turn signal.....wave rectifier may be my only option.....no way to mount another LED
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Oh, I thought you had a 2-wire AC input.

    A fullwave bridge probably won't work for your application.

    Since changing vehicle lighting may violate laws in various areas, we don't help people with that kind of thing anymore. There's no way we can be assured that modifications you make will still be within applicable regulations and manufacturer's specifications. This IS a safety issue - yours, and the people on the road with you.

    My only recommendation is that you keep the vehicle lighting exactly as how it came from the manufacturer, as it was approved by the appropriate regulating authorities.
     
    Holder350 likes this.
  5. Holder350

    Thread Starter New Member

    Jan 17, 2010
    7
    0
    I am complying with all local laws, thus the reason I am trying to get this to work.....

    All parts are DOT approved, the way its wired sucks...I am almost sure that a full wave bridge will work, it will work just like the flip flop poles of AC current, just not quite as fast.

    Thanks for all the help!
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Many older vehicles have lamps with two filaments; one is for parking/running lights, and the other for turn signal/brake lights.

    The body of the base of the bulb is grounded. There are two contacts on the base of the bulb.

    If you change the bulb from incandescent to an LED, it will draw a different amount of current, and the flasher will likely no longer flash.

    I thought you were dealing with a low voltage AC system, not two different DC lines and a ground.

    In any event, you haven't described how it is currently wired very well, so it's going to be difficult to help you.

    I don't know what's wrong with just staying with incandescent bulbs - they last for several years at least.
     
Loading...