adding a flashing colon to my clock

Discussion in 'The Projects Forum' started by magnet18, Jun 5, 2011.

  1. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    OK guys, the clock is coming together, and I finally got the time setting figured out (had to make some changes), so now it's time to figure out how to add some features.

    I was thinking that with some quad and gates I can make an alarm pretty easily, but I was wondering how to do a blinking colon, like the one shown in this video-
    http://www.youtube.com/watch?v=4bl5kSr8C3Q

    I already have the tubes (and like 50 of them :p), they're IN-24, datasheet here- http://tubehobby.com/datasheets/in24.pdf, scroll down for translation of the important stuff.

    So basically what I need to do is reverse the voltage twice a second to get the blinking (theres 2 little metal plates in there, the cathode glows and the anode doesn't, it's designed to be reversed).

    I already have the 2 Hz signal from the 4060, but after that everything I've drawn up in my head has hit brick walls.

    Ideas?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    I have some NE-2's, but they don't look the same for the colon with the half glowing, half not glowing.
    And I don't mind the color. :)
    And I have 60 of these. :p
     
  4. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Well, I was thinking that a 4013 could be used with the NPN MPS-A42 and it's PNP equivalent, thoughts?
     
  5. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Your idea should work, connect 4013 as toggle FF. Might need to adjust 20K to give desired brightness. With 300V rating, might not need V divider.
     
  6. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    That would work, but theres only 2 contacts on the tube.
    Anode, and cathode.
    I have an idea I worked on a bit during school, I'll draw it up in a bit and see what you think...
     
  7. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    This is the first thing that comes to my mind, but I need to switch the high side...
     
  8. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    [​IMG] still gets tied to D, right?
     
  9. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    For FF, yes NotQ to D. Here is another attempt, assuming that you have MPS-A92, PNP hi-V. 0r other sim.
     
  10. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Thanks, I'll give it a try.
    I need to order some transistors though :(
     
  11. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    How does this flash? It seems to me like the dots will toggle back and forth.
     
  12. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    I was short of time before, think it can be simplified a bit:
     
  13. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Same question: How does that make a flashing colon? It looks to me like it makes the two dots flash alternately.

    EDIT: I found a picture of the IN-24. Magnet, how can you make a colon out of this?
    This is a colon:
    :
    Apparently, you are just trying to make the two plates flash alternately, but you sure led me down the garden path by calling that a colon.:mad:
     
    Last edited: Jun 7, 2011
  14. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    When you flash the plates alternately it looks like a colon to me.

    I linked to the video in the first post showing the effect I wanted, I didn't know that it wasn't still considered a colon.

    Is there a specific name for that thing between the numbers on a clock?
     
  15. #12

    Expert

    Nov 30, 2010
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    If you flash them quickly, persistence of vision will make them look like a colon, but it will look like it's always "on".

    I don't know what single word would describe 2 dots, one above the other, alternating, but I do hope you get this working soon. Every time I read your title my mind goes to "intestinal problems". I surely wouldn't want my colon to flash!
     
  16. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Sorry I missed the video. I guess I have a mental block or something.
    That is definitely not a colon, but it is definitely some alternately flashing lights.:D
    I personally think the classic flashing colon would look better. I would probably get 4 of these neon dots (not sure which model). I like the INS-1, but it might be too small.
     
  17. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    I actually just ordered ten more IN-2's for $2.50, I'm considering using those...
    I'll build both and see which I like better.

    I like the INS-1's also, but they're definitely much too tiny (5mm!)
    I'll consider them if I ever make a smaller clock.
     
  18. Wendy

    Moderator

    Mar 24, 2008
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    A simple neon connected to 120VAC through a 1MΩ resistor will light up both leads. High voltage DC will light up one lead (which is a point).
     
  19. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    How about an optical coupled triac driver, 22k & 120VAC. Use 1 sec. ,50% duty cycle to drive coupler, & you have blinking colon. [ If 120 V AC is high enough to strike ]
     
    Last edited: Jun 8, 2011
  20. SgtWookie

    Expert

    Jul 17, 2007
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    It needs 160v to strike.
     
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