With each touch on S1, an output of 4017 is activated, this in sequence 3, 2, 4, etc. These outputs can excite power stages with relays or other commands. The 555 works as monostable, generating pulses of constant duration. The circuit is from my book Robotics, Mehcatronis and Artificial Intelligence, published in the United States. The 4017 can be on a remote controlled circuit.
