Timer for scoreboard using counters

Discussion in 'The Projects Forum' started by maan18, Feb 12, 2011.

  1. maan18

    Thread Starter New Member

    Feb 12, 2011
    Hi! I'm new here, I'm having trouble coming up with a circuit on a scoreboard's timer. I've already designed the counter for the scoring using a 74293 counter mod 100 but my teacher required the scoreboard to include a timer for the game which is basketball. I really have no idea how to make the counter generate a repeating pulse to trigger the second, minutes and hour from running, getting the pulse from the master milliseconds. please help. thank you very much.:(
  2. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    If you have a clock source in ms, it should be easy to divide by 10 to get 100th, again for 10ths and finally again for a 1hz input. Then use that signal for your game timer clock. Search here for different clock and timer circuits. You will also have to consider in your circuitry the ability to pause and resume. A "nice to have feature" would be to swict the display to hundredths of a second in the last 9.99 seconds of the game...
  3. maan18

    Thread Starter New Member

    Feb 12, 2011
    what would be the best IC to use as a clock? is it the 555 timer?
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    A 555 is not stable enough for a scoreboard clock. It's simpler to let the line voltage do the work, as the stability is very good.

    The circuit attached will generate a 60 Hz clock pulse from a transformer. Life is easier with these projects if you use CMOS logic, as it will run on any voltage between 3 and 15 volts. A 12 volt supply is pretty easy to come by.

    Count the pulses down by 6 and you have a .1 second clock, or by 60 and you have a 1 second clock.