This circuit is a 4-bit binary ripple counter. All the JK flip-flops are configured to toggle their state on the falling transition of their clock input, and the output of each flip-flop feeds into the clock of the next flip-flop. Thus, when each bit changes from 1 to 0, it "carries the one" to the next higher bit.
This page is a utility for simulating 4-битный счетчик пульсаций online with specified initial values.










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