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TTL Clock with 7447 7490 and 7400 IC's

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by RODALCO, Nov 28, 2006.

  1. ben7

    ben7 Member

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    Can I make the same clock with CMOS CD4xxx series chips?

    CD4059-divide-by-60 for 60hz(mains Freq.) in, and 1hz out
    CD4511-BCD 7-seg display driver
    CD4029-Up/Down BCD counter
    CD4011-as NAND gates
    and what chip do I need to to replace your SN7413 chip?

    Help is greatly appreciated!

    -Ben
     
  2. RODALCO

    RODALCO Well-Known Member

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    CMOS clock

    For the 7413 chip a 4093 can be used as that has the Schmitt trigger built in.
    The 7413 makes square waves and takes the noise out of the reference sine wave.

    Probably not a bad idea to start a new thread for a CMOS clock to keep all information together pertaining to the CMOS clock project.
     
  3. ben7

    ben7 Member

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    Thanks!

    I don't know all the different CD4xxx series chips.
    I might start a new thread for a cmos clock sometime soon.

    -Ben
     
    Last edited: Oct 31, 2010
  4. dave

    Dave New Member

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  5. tab70

    tab70 New Member

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    I am in the process of designing a TTL clock. One of the features I would like to add is the blinking 12:00 you see when you first power up a digital clock. Right now I am at a stand still on how to do this. Any suggestions or ideas would be greatly appreciated. Thanks is advanced.
     
  6. seasame

    seasame New Member

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    7490 clock buttons

    can anybody tell me how to add buttons for minutes and hours in th 7490 ic based clock in which both mod 6 and mod 10 counter are constructed from 7490 ics,,,itsa 24 hour clock......plz explain it with schematic.............
     
  7. audioguru

    audioguru Well-Known Member Most Helpful Member

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    In the 70'ies (36 years ago) I used old fashioned 74xx and 74LSxx logic ICs until I tried CD4xxx and 74HCxxxx Cmos ICs. I threw away my TTL cookbook and bought a Cmos cookbook and used Cmos ever since. I think old fashioned teachers still use old fashioned TTL logic ICs.

    36 years ago every school kid made a TTL clock. Now every school kid makes a programmed PIC clock. EXCEPT NOT IN 3RD WORLD COUNTRIES.
     
  8. RODALCO

    RODALCO Well-Known Member

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    Look at the schema at the beginning. by adding NPN transistors at point F.
     
  9. condonhan

    condonhan New Member

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    Could you please share with me your schematic. I need it for my project.
    Thank you in advance. ^^
     
    Last edited by a moderator: Feb 2, 2012
  10. cattielyn

    cattielyn New Member

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    can post the schematic again?
    please :)
     
  11. mazaismo

    mazaismo New Member

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    Please can u help me with the circuit diagram of this digital clock because i have a project on digital clock
     
  12. RODALCO

    RODALCO Well-Known Member

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    All the info is in this thread. Only parts required.
     
  13. iec2010032

    iec2010032 New Member

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    i want to make a reset button for the mod-6 counters. can u please help me? :)
     
  14. cyrilcuthbert

    cyrilcuthbert New Member

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    I'm getting a hard time in this, it counts like this: 01-02-03-04-05-06-07-08-09-20-21-22 then back to 01..... pls. help :D
     
  15. RODALCO

    RODALCO Well-Known Member

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    Check the 7400 connections. That decodes the 24 hours. Have you connected it to the correct A and B inputs ?
     
  16. cyrilcuthbert

    cyrilcuthbert New Member

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    yes, i'm pretty sure i've done it correctly
     
  17. Mike odom

    Mike odom Active Member

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    we built a Master Clock system for ships using a hermetically sealed oscillator (running in an insulated oven at a constant temperature), and even at 6ppm error, you could still see up to 15 seconds of error a month... a 555 is not any where near this stable or accurate, even most watch crystals have more error than this, most crystals are rated in the % and ppm/°C. Even the 3.58MHz colorburst crystal used in a color tv is reset into sync at the start of every line sent.

    The most stable and accurate time base will be derived from line frequency as it is adjusted (usually around midnight) to be a 60 HZ average over the day. A 555 may look like it's giving you 60Hz, but any accumulation of timing periods (like a clock) will show a very large error in as little as a week, or even a day.
     
    Last edited: Nov 18, 2012

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