Experiment 3 - The 4-bit Counter

With four T flip-flops in a chain you build a 4-bit counter. The inverted output of a T flip-flop is connected to the input of the next T-flip-flops...

Circuit diagram of a 4-bit or mod-16 counter with T flip-flops

Illustration states of a 4-bit counter.

Each time you press the pushbutton switch S1, the 4-bit counter counts from 0 to 15, before it falls back to 0. Therefore it is referred to as a modulo-16 or mod-16 counter.

The result is displayed as a binary number by Q0 to Q3.

Circuit 4-bit or mod-16 counter with JK flip-flop. (Enlarge)

In the next experiment, you get to know more modulo-x counters...