Sequential control circuit capable of sequencing through a number of stable states in a predetermined order

摘要

A sequential control circuit capable of sequencing through a number of stable states in a predetermined order, starting from a predetermined stable state and sequencing in either of two opposite directions. A contact maker having two transient positions is connected to a timing circuit and to a logic circuit. In response to assumption by the contact maker of one of its transient positions, the timing circuit provides a timer signal delayed with respect to the interval of that transient position. The logic circuit sequences through a number of output conditions corresponding with the stable states in a direction determined by the particular transient position. The logic circuit includes circuitry for placing the circuit in a predetermined one of the output conditions upon initial start up.