Building a circuit with dual JK flip-flops & NAND chips

Thread Starter


Joined Jan 17, 2011
Hello and thanks for viewing my question,

I am working on designing a Moore sequential circuit. You can take a look at this link which has more information about what the design entails:

I believe that I have correctly figured everything out to determine what J1, J2, K1, K2, and Z are equal to.

I am now having a lot of trouble and need somebody to draw a final design on paper, using 2 JK Flip-Flops and NAND gates.

The following link shows the diagram from which needs to be drawn on:

I have figured out how to connect the whole thing using one switch, but have spent hours and I cannot design it with the second switch for some reason. I might be missing something.

The chip diagrams are here:




I would greatly appreciate if you could help me out by printing out the diagram, connecting the wires to the appropriate chips, switches, led, etc. and scan it back so I can view a posted link and better understand what I need to do to get this all connected and working on my breadboard.

Thank you very much for your time and efforts! Have a great day.


Joined Feb 28, 2011
First let me suggest to you that you might not understand it as well as you think. In the first state truth table you have the Z output labeled with 0's & 1's. Don't you think since the state machine's output remains the same or toggles, that the Z output should be either Z or /Z? I think once you grasp that it should either toggle or not might help you to understand how the remainder of the tables you have should be filled out. Once you are there you should see the connection between Z of your table and the Q of the flip-flop. Once there, I think you will see how to connect the wires.