# 9-0 Counter using J-K Flip Flop

Discussion in 'The Projects Forum' started by batoinkx, Oct 15, 2014.

1. ### batoinkx Thread Starter New Member

Nov 13, 2012
6
0
I'm currently designing my 9-0 counter for my project.
I simulated my design and the output is just 9,8,5,4,1,0 i think my j2 and k2 has a problem.
Kindly check my work sir.

2. ### tshuck Well-Known Member

Oct 18, 2012
3,531
675
Your circuit worked when I simulated it.

3. ### MrChips Moderator

Oct 2, 2009
12,624
3,451
You have J1 = Q1'. Q0' . (Q2 + Q3)

Since this is the Q1 J-K flip-flop this becomes

J1 = Q0'.(Q2 + Q3)

4. ### batoinkx Thread Starter New Member

Nov 13, 2012
6
0
Here's my simulation sir, it didnt worked. 9,8,5,4,1,0

5. ### batoinkx Thread Starter New Member

Nov 13, 2012
6
0
sir what rule did you used to simplify j1?

6. ### batoinkx Thread Starter New Member

Nov 13, 2012
6
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BTW this is a 9-0 counter, my thread subject is wrong my bad sir.

Edit: Title corrected to show 9-0 Counter using J-K flip-flop.

Last edited by a moderator: Oct 15, 2014

Oct 2, 2009
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3,451
8. ### batoinkx Thread Starter New Member

Nov 13, 2012
6
0
oh tnx a lot sir, how about my circuit or k mapping? I simulated it using Logism, its not working. It keeps on skipping 7,6,3,2 those state has a high Q2 output.

9. ### MrChips Moderator

Oct 2, 2009
12,624
3,451
Then obviously, check your J and K inputs to Q1.

You forgot to connect Q0' to K1

10. ### tshuck Well-Known Member

Oct 18, 2012
3,531
675
Yup, you missed the $\overline Q_{0}$ to $K_{1}$ connection...

11. ### batoinkx Thread Starter New Member

Nov 13, 2012
6
0
Yay. Thank you so much sir. More I2R to this site.

12. ### MrChips Moderator

Oct 2, 2009
12,624
3,451
Now try removing Q1' from the J1 expression.