Starting a counter

Discussion in 'The Projects Forum' started by simo_x, Jan 2, 2011.

  1. simo_x

    Thread Starter Member

    Dec 23, 2010
    Hello, I am working with a little project wich use a preselect counter.

    Someone told me that when the power is supplied, you never know exactly at wich sequence the counter will start to count, so in practice the probability it start from 0000 is never 100%, so if it is true I need to work on the Master Reset of this counter, which is the 40163.

    So I thinked to use a RC as this:

    where "Analog Out" is the output to the Master Reset Input, which is activated with a logic 0.

    With this configuration, changing the value to 10uF for the capacitor, when power is supplied, in 0.5 second the logic state of the output change from 0 to +.

    I am not sure if it is ok to start the counter from 0000. Is it?

    Thank You for your suggestion.

  2. edgetrigger


    Dec 19, 2010
    Analog output has to be connected to the master reset point or the clear pin. And what you have mentioned as pin has to be connected to Vcc, so that you get the clear pin pulled low when the Vcc stabilises.
  3. Jony130

    AAC Fanatic!

    Feb 17, 2009
    For reset at start-up I use 100K+100nF.
    And it is always work for me.
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    You could always set up a 'logic check' to insure you get the proper state set before the counting starts.

    A four input NAND/AND gate could look at the output states and only give a signal out when the counter is at 0000. This could be a count enable signal, so you know the count will always start at 0000
    Last edited: Jan 2, 2011
  5. simo_x

    Thread Starter Member

    Dec 23, 2010
    OK, thank you for your clarifications. ;)