Reverse Polarity circuit?

Discussion in 'General Electronics Chat' started by perni_a, Jul 4, 2011.

  1. perni_a

    Thread Starter New Member

    May 12, 2009
    Hi guys,
    long time reader, first time poster.

    I am currently undertaking a personal project that is stretching the memory a bit in terms of circuit design.

    Essentially this is what I need to happen. Designed to work on 12VDC in car system, for a popup dash display monitor.

    When power is applied (Ignition ON), the motor in the pop up unit will spin clockwise to open the monitor unit.
    When the unit reaches a limit switch, the motor is stopped.

    When the power is disconnected (using ignition switch- but still powered by constant 12v), the motor will turn in the opposite direction (reverses the polarity), until it reaches a second limit switch on the other side, then the motor will stop, in preparation for the ignition to be turned on again (repeat of cycle).

    Ideally, I would like a manual control switch to move the unit back or forth, depending on what position it is in. But this is optional to my needs.

    The monitor frame already has limit switches installed, and they are normally open switched (completes the circuit when limit is reached). Ideally I would like to keep them this way, but pleae let me know your suggestions.
    thanks guys and girls.
  2. #12


    Nov 30, 2010
    Oops. "Car" is a dirty word here. The bosses will not let this subject be discussed.
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
    Look up kksmith, Tytle page upper right- little white box for posting of lifting platform, esp. Sgt Wookie's post.
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
    Also found this " Drawr Operer". Limit switches are NC rather than yours which are NO. At least its a hint.