RC for Clock and clear

Discussion in 'The Projects Forum' started by simo_x, Jan 27, 2011.

  1. simo_x

    Thread Starter Member

    Dec 23, 2010
    200
    6
    I all, I have a circuit (I attacched it to the post). It's a dice, and I have a little question:

    If in the circuit I connect R5 (changing it from 1K to 10K) to the RC of R3 an C3, I can erase R4 and C4 from the circuit, correct?

    The purpose is to clear the MR in a shorter time than give a shot to CLK.
    I Think my idea is correct.. Could you confirm me that please??

    Thank you for your replies.
     
  2. simo_x

    Thread Starter Member

    Dec 23, 2010
    200
    6
    Well, I think my idea was bad, because capacitor charging time will always depend on R3*C3 without any delay on R5.
     
  3. ifixit

    Distinguished Member

    Nov 20, 2008
    639
    108
    Hi,

    • Why do you want to change it? Doesn't work the way it is?
    • D2 should be the other way around. Typo?
    • The Q1 clock enable circuit is only needed if the circuit is powered up with the push-button depressed. Right?
    • Could you use pin 4 of the 555 IC to keep the clock off until power is up?
    Regards,
    Ifixit
     
  4. simo_x

    Thread Starter Member

    Dec 23, 2010
    200
    6
    Just to simplify the circuit.. I thought it maybe works, but not, two Rc are needed.
    Yes, Q1 will give a PGT. Yes, I can use pin 4.

    EDIT: do you think is really bad working on the clock in this way?
    Thank for your reply.
     
    Last edited: Jan 28, 2011
  5. ifixit

    Distinguished Member

    Nov 20, 2008
    639
    108
    Your way is okay, however, R5 and Q1 are not needed if pin 4 is used there-by saving some components. R4 and C1 would connect to pin 4.

    If you have a bread board of the circuit you could try it and see if you like how it works.

    Regards,
    Ifixit
     
  6. simo_x

    Thread Starter Member

    Dec 23, 2010
    200
    6
    Which way?
    One RC or two separates RC?
    I am already mounting assembling the circuit..
    Regards.
    Simo
     
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