Portable DC powered variable power supply.

Discussion in 'The Projects Forum' started by brom77, Oct 23, 2009.

  1. brom77

    Thread Starter New Member

    Oct 23, 2009
    Good day.

    I am new here (as indicated by my enormous post count...). I'm currently attempting to construct a portable -12 to +12vdc power supply that does not require an ac source of power. This power supply is to be used to zoom/focus motor-zoom camera lenses (output through two pin pairs in an 8-pin connector). I can "hamfist" my way there by making four seperate circuits (focus in, focus out, zoom in, zoom out), but I'm certain there is a more efficient way to do so. I know that I'll only need to adjust one paramater (zoom, focus) at a time.

    The lens requires a 0-12volt input to drive it's motors, with polarity determining direction of travel. I need the supply to be DC powered, as they are all in rather inconvenient locations to route AC power.

    I was considering using a 5-position rotary switch for parameter selection (fifth position being off), and a slide switch to adjust magnitude.

    I suppose the gist of my question is how best to accomplish this within a portable "box' without requiring outside power, and keeping things as portable as possible.

    Thanks for your time,

  2. beenthere

    Retired Moderator

    Apr 20, 2004
    We need more information about those motors. The statement -
    leaves some doubt as to the nature of the motors (AC or DC). Also, the current draw is important.

    You can reverse a DC motor with a switch that reverses polarity - no need for a dual DC supply