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Homework Help: Help with the Project

  1. May 28, 2012 #1
    Hi All,

    I am doing this project where I want to implement a start stop timer. I want to use one start and one stop button (or a single button for both) and interface them with 555 timer. The 555 timer I would like to configure for one second. The output I would like to display on the 3 seven segment displays (up to 3 digits 0,1,...999 etc). So, once I press the start button the 555 timer will start counting the seconds and display the same as 1,2 etc upto 999 on the seven segment displays, andd stop once the stop button is pressed and hold the value. Could somebody please guide me how to do this? I donot want to use microcontroller. I know how to configure the 555 timer for 1 sec but remaining part is little bit confusing for me.

    Thanks in advance,
  2. jcsd
  3. May 28, 2012 #2
    Pipe the pulsed output into cascade of three BCD Counters (eg 4510) and the output of the BCD Counters to the three 7-seg displays via 7-seg decoders (eg 4511)

    As for the start/stop - the hint word to search for is 'flip flop'
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