SEQUENTIAL CIRCUIT #10 – TWISTED RING COUNTER

 

ANIMATION

 

Below, you can see what the Twisted Ring Counter (also known as the Johnson Counter) does. 

 

Here’s a summary:

  • Every clock rise, it shifts the value of D from the left to the right.
  • When the new arrives at the far right, it sets the first D to the opposite value (Q1).

 

Johnson+digital+counter+circuit+diagram+using+D+flip+flop+7474+%25283+bit4+bit%2529+with+animation+simulation+animation Johnson digital counter circuit diagram using D flip flop 7474 (3 bit/4 bit) with animation/ simulation

 

TRUTH TABLE

 

State

Q0 (LED #1)

Q1 (LED #2)

Q2 (LED #3)

State 0

0

0

0

State 1

1

0

0

State 2

1

1

0

State 3

1

1

1

State 4

0

1

1

State 5

0

0

1

 

Note: After State 5, the circuit returns to State 0.

 

SOURCE

 

http://www.circuitsgallery.com/2012/07/johnson-digital-counter-circuit-diagram.html

 

PROJECT EXPECTATIONS

 

Use the 555 timer to provide a clock signal to four D Flip Flops connected together to form a Twisted Ring Counter. 

 

Show your counter working with LEDs to Mr. Campeau.