Ring and Johnson Counters

RING AND JOHNSON COUNTERS

AIM:

To design and set up four bit Johnson and ring counters .

MATERIALS AND TOOLS REQUIRED:

ICs 7476, 7474 and trainer kit and digital trainer kit, Power supply.

THEORY:

Ring counter and Johnson counter are basically Shift registers. It is constructed using JK flip flops by connection Q and Q’ outputs one from the flip flop to the J and K inputs of the next flip flop. The outputs of the final flip flop are connected to the inputs of the first flip flop. 

Johnson counter The modulo number of a ring counter can be doubled by making a small change in the ring counter circuit.  The Q’ and Q outputs of the last flip flop are connected to the J and K inputs of the first flip flop respectively.

Circuit Diagram:

PROCEDURE:

1. Set up the ring counter and set any Q output using PRESET and apply mono pulses using d-ebouncer switch n the trainer kit to the CLK input.
2. Note down the states of the ring counter outputs on the truth table for successive clocks.
3. Repeat the steps 1 and 2 for the Johnson counter.

RESULT:

              Four bit Johnson and ring counters are designed.