Digital actuator including feedback representation of the stepper motor winding energization state

Claim 1

DIGITAL ACTUATOR APPARATUS COMPRISING AN ELECTRICALLY-EXCITED MOTIVE DEVICE FOR PRODUCING A MECHANICAL OUTPUT MOVEMENT OF PREDETERMINED MAGNITUDE IN ONE OF TWO POSSIBLE DIRECTIONS RESPONSIVE TO EACH CHANGE IN ELECTRICAL EXCITATION THEREOF, SAID MOTIVE DEVICE PRODUCING MOVEMENTS IN THE TWO DIRECTIONS RESPONSIVE TO ELECTRICAL EXCITATIONS THEREOF IN ACCORDANCE WITH A PREDETERMINED REPETITIVE SEQUENCE, CONTROLLER MEANS PRODUCING TWO DIFFERENT CONTROL SIGNALS TO COMMAND OUTPUT MOVEMENTS OF SAID PREDETERMINED MAGNITUDE FROM SAID MOTIVE DEVICE IN DIFFERENT DIRECTIONS, LOGIC CIRCUIT MEANS FOR CHANGING THE ELECTRICAL EXCITATIONS OF SAID MOTIVE DEVICE RESPONSIVE TO EACH OCCURRENCE OF SAID CONTROL SIGNALS, AND MEANS APPLYING TO SAID LOGIC CIRCUIT MEANS ELECTRICAL INPUT SIGNALS CHARACTERIZING BOTH SAID CONTROL SIGNALS AND THE STATE OF THE ELECTRICAL EXCITATIONS IN THE SEQUENCE OF SAID ELECTRICAL EXCITATIONS OF SAID MOTIVE DEVICE, SAID LOGIC CIRCUIT MEANS BEING WIRED TO RESPOND TO SAID ELECTRICAL INPUT SIGNALS WITH CHANGES IN SAID ELECTICAL EXCITATIONS ACCORDING TO SAID PREDETERMINED REPETITIVE SEQUENCE.