MODIFICATION S2 is a SPDT switch, when positioned toward B, it responds to the pressing of S1 and steps with each trigger from S1. When S2 is moved toward A, pressing S1 does the following things: T1 and T2 instantly latches powering the timer IC 4060 via T2 and T3. IC 4060 starts clocking the IC 4017 for the required actions. Putting S2 back to point B resets the circuit to its previous mode, that is to the manual mode. However to reset the IC 4017, it will need to be switched OFF and then switched ON again.