Newbie help with 7 segment display

Discussion in 'The Projects Forum' started by _Thoth_, Jun 15, 2010.

  1. _Thoth_

    Thread Starter New Member

    Apr 8, 2010
    19
    1
    For starters I have absolutely zero knowledge of electronics, more of a software guy, so please be gentle.

    I need to build a standalone 7 segment display controller to fit inside a movie prop (IV pump). I have the displays (MAN3440A015 H64) from the original circuit board which I was hoping to reuse as they mount perfectly inside the housing. The displays (there are four of them) need to show a static number, and that's it, any number will do. Simple for some, impossible for me.

    Essentially I want a solution that can just be given power and the number displays, and never has to change.

    Anyone know of a standalone kit or controller or anything really ?

    Thanks, Glenn.
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    If the number doesn't have to change this is really simple. Find LED display's you like then get back with us. We'll need the part number though, since it will determine the wiring.

    I assume you're going to use a 9V battery, if not let us know what it will be.
     
  3. n1ist

    Active Member

    Mar 8, 2009
    171
    16
    The number he mentioned (MAN3440A) is a common cathode display. For each digit, connect pins 4 and 12 together to the negative of your battery. Each segment you want lit needs to be connected to one side of a resistor (try 390 or 470 ohms for a 6 volt battery - 4 AA or C in series). The other side of each resistor gets connected to the positive terminal of the battery. You need a separate resistor per segment.
    Look at the datasheet (http://www.datasheetarchive.com/pdf-datasheets/Datasheets-5/DSA-83953.pdf) to see the pinout
     
  4. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    Cool. I missed the part number, data sheets are always nice. The only think left is power supply, it will determine the resistor values.
     
  5. _Thoth_

    Thread Starter New Member

    Apr 8, 2010
    19
    1
    Wow, so quick ! Awesome.

    I am looking into the specs on the Ensign transformer on the unit to see if I could just use that directly, will post when I get the specs.
     
  6. _Thoth_

    Thread Starter New Member

    Apr 8, 2010
    19
    1
    OK, no luck with Ensign as it is, apparently, a proprietary transformer, but I measured with the good ol' multimeter at 30V.

    Cannot measure the current but it has a 0.5A fuse, so I would guess less than that, but what do I know.
     
    Last edited: Jun 17, 2010
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