School Project Help!

Discussion in 'Homework Help' started by Transon, Nov 4, 2013.

  1. Transon

    Thread Starter New Member

    Nov 4, 2013
    Okay, I've recently began to study electronics on school and tomorrow I got a BIG test, and I need big help because I cant seem to understand how I start the circuit.

    Its a Binary counter with 4 JK-Flip Flops, and they're inverted at the start as you can see.

    Here is the whole circuit.

    This is the one I'm not sure of, how am I supposed to make those "switches" with 0 and 1.
    Image of the task.

    Please give me some tips :)
  2. Wendy


    Mar 24, 2008
    It looks OK to me. I'm not sure what the question is. Generally it is assumed (and you have the set/reset lines wired to make it so) that a counter starts on 0000.

    These flip flops toggle on the negative edge, so as the previous number goes to zero the next digit goes to a one.

    I used to bread board those circuits for fun when I started out, over 40 <mumble> years ago.
    Transon likes this.
  3. vini_i

    New Member

    Apr 19, 2010
    some flip flops have a set and reset built into them. the two switches that you mention are to set (store a one) or reset (store a zero) in the flip flop regardless of what is at the input.

    when a flip flop first powers up the state that is stored in it is unpredictable. it can be a zero or one. so the set and reset functions are used to change the state of all the flip flops to a particular value so that everything else is predictable.

    this is generally invoked by some device that can sense a power up condition and change the state of all the flip flops to a set state.

    or in this case to reset the counter to either all zeros or all ones.