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Odd 7-segment display

Discussion in 'Electronic Repair' started by John E., Feb 14, 2007.

  1. John E.

    John E. Guest

    Came across a 90's vintage IR controller for printing industry (drives Q-H
    lamps for drying ink in the paper path) that uses a single-digit 7-segment
    display that looks like a nixie tube (more like a white-hot wire segment)
    display. The 16-pin DIP socket is marked IEE-Atlas, and the single-digit
    display is marked "IEEFFD21 5DX C". Each digit display is 15 pin on a 16 DIP
    pattern.

    I've done the requisite Google, but come up with nothing. The drivers on the
    PCB are MC14511BPC which is a standard CC LED 7-segment driver.

    What are these? They don't look anything like LED segments (I can see each
    wire-like segment behind the glass front of each digit's display). Can I just
    replace these with a common LED display? Or are replacements available?

    Thanks,
     

  2. Incandescent wires? RCA called them Numitrons.

    http://www.sphere.bc.ca/test/nixies2.html

    <http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GWYA,GWYA:2006-31,GWYA:en&q=Numitron>


    --
    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
     

  3. Search for: IEE FFD21


    --
    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
     
  4. rebel

    rebel Guest

    Once upon a time there were incandescent 7-seg annunciator devices, under
    various names. Minitron and RCA's Numitron are two names, but do a google
    search on "incandescent" and "7-segment" for heaps of background.
     
  5. John E.

    John E. Guest

    Search for: IEE FFD21

    Thanks.

    No replacements available.

    So, since this uses the MC14511 driver, which was designed for LED 7-segment
    displays, all I have to do is provide resistors to each element and rewire
    for a common-cathode LED display, right?

    Thanks,
     
  6. John Fields

    John Fields Guest

     
  7. Does it heat up? Voltages?



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  8. Arfa Daily

    Arfa Daily Guest

    When I was young and enthusiastic, I built a frequency counter that used
    these. I think it was a Practical Wireless design. It's still around
    somewhere ...

    Arfa
     
  9. James Sweet

    James Sweet Guest


    Sounds like a Numitron incandescent filament display. These are getting
    very hard to come by.
     
  10. John E.

    John E. Guest

    James Sweet sez:
    Purchasing LED 7-segment replacements and associated kit (resistors, etc.)
    tomorrow to convert to a 21st century technology.
     
  11. John E.

    John E. Guest

    So, since this uses the MC14511 driver, which was designed for LED
    A little clarification, please...

    I'm all ready to start looking for a CC display, when I look at the data
    sheet for MC14511BCP and it has example circuit hookups for both CC and CA.

    I thought a driver output was for one or the other "gender", either CC or CA.


    Am I reading this right? Can I use either without further need of other
    configuration or circuitry? Seems too good to be true...

    Thanks,
    Dave
     
  12. John E.

    John E. Guest

  13. John E.

    John E. Guest

    A second reading of the ds shows that, indeed, a transistor is needed to use
    a CA display with the MC14511.

    [gotta stop these early morning designs...]
     
  14. I would do happier with you if you stopped changing thread
    titles.
     
  15. John E.

    John E. Guest

    I would do happier with you if you stopped changing thread
    Sorry, I didn't know this caused a break in thread. My reader simply inserts
    the re-titled post in the same thread, just with another title. I should have
    realized that not all reader apps behave the same.

    Sincere apologies. Will avoid temptation in future.
     
  16. Most readers use the message ID and work correctly.


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  17. I appreciate it. It is not so much a problem with broken
    threads, for me, as much as it is that I remember the thread
    title of threads I have been reading. When you change the
    thread title, I have to go back and review earlier messages
    to remember what subject we are talking about.
     
  18. They used to be popular in petrol pumps in the UK (they are
    readable in quite bright sunlight).
     
  19. John Fields

    John Fields Guest

    ---
    It is. [too good to be true]

    The device, by itself, is designed to drive a common cathode display
    as shown in the upper left hand corner on page 6 of this data sheet:

    http://www.onsemi.com/pub/Collateral/MC14511B-D.PDF

    Immediately across the page from it is the common anode
    configuration, which requires an additional transistor and resistor
    _per segment_ .
     
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