# 2 bits counter with JK ff

#### zestyphoenix

Joined Dec 9, 2015
3
Hey guys I need this circuit for my lab assignment tomorrow but I didn't get flip-flops really well. The circuit will count 00-01-10-11(in two seven segment display) when input is 1 and 11 to 00 when input is 0.
Here is a list of items that I can use:
ICs: 7400 (NAND gate) (x3), 74109 (KJ F-F) (x3), 7446 (BCD-Seven Segment Decoder) (x2)
 Switch (x3)
 Seven Segment Display (x2)
 470Ω (x8)

Anybody can post me a circuit that will work?

#### RBR1317

Joined Nov 13, 2010
595
So have you decided whether to make a synchronous counter or a ripple counter with the J-K FFs?

#### WBahn

Joined Mar 31, 2012
26,398
Hey guys I need this circuit for my lab assignment tomorrow but I didn't get flip-flops really well. The circuit will count 00-01-10-11(in two seven segment display) when input is 1 and 11 to 00 when input is 0.
Here is a list of items that I can use:
ICs: 7400 (NAND gate) (x3), 74109 (KJ F-F) (x3), 7446 (BCD-Seven Segment Decoder) (x2)
 Switch (x3)
 Seven Segment Display (x2)
 470Ω (x8)

Anybody can post me a circuit that will work?
So you don't want to put in any effort at all? You just want someone else to give you a circuit that will work?

#### zestyphoenix

Joined Dec 9, 2015
3
Synchronous counter.

#### MrCarlos

Joined Jan 2, 2010
400
Hello zestyphoenix
According to what I understand from what you say is that you were assigned to do an up-down counter 0-3, 3-0 with Flip-Flop's.
But. . . There are not very well understandable things in your statement:
Why two Display's ??.
Are you going you use a switch to the clock pulse ??. You'll need a circuit called de-bounce.
In the list of items that you can use:
The numbers in parenthesis are the number of ships or the amount of NAND gates, Flip-Flip's, switches ??.

#### WBahn

Joined Mar 31, 2012
26,398
I'm guessing that the two displays is because they want it displayed in binary (of course that can be done very easily without the use of a decoder (or, using a common anode display, without any logic at all provided the FF can sink enough current for four segments).

#### zestyphoenix

Joined Dec 9, 2015
3
Hello zestyphoenix
According to what I understand from what you say is that you were assigned to do an up-down counter 0-3, 3-0 with Flip-Flop's.
But. . . There are not very well understandable things in your statement:
Why two Display's ??.
Are you going you use a switch to the clock pulse ??. You'll need a circuit called de-bounce.
In the list of items that you can use:
The numbers in parenthesis are the number of ships or the amount of NAND gates, Flip-Flip's, switches ??.
Two display because it will be in binary and yes the numbers in parenthesis are the number of that gates.