Motor control system having a counter responsive to a modulated pulse train

Claim 1

A CONTROL SYSTEM INCLUDING AN ARRANGEMENT FOR MODULATING A WAVEFORM OF REGULARLY-SPACED PULSES IN ACCORDANCE WITH INFORMATION, IN THE FORM OF COMMAND PULSES FOR DIRECTING MOVEMENT OF A MOVABLE LOAD DERIVED FROM AN EXTERNAL SIGNAL GENERATING MEANS COMPRISING, IN COMBINATION, OSCILLATING PULSE GENERATING MEANS TO GENERATE TWO SETS OF PULSES RESPECTIVELY TIMED WITH THE PHASE FROM OPPOSITE HALF CYCLES OF OSCILLATION TO OCCUR WITH PULSES IN THE TWO SETS SPACED BETWEEN EACH OTHER, THE FIRST SET OF PULSES COMPRISING SAID REGULARLY-SPACED PULSES, A COUNTER FOR COUNTING SAID REGULARLY-SPACED PULSES, SAID COUNTER HAVING A NORMAL CYCLIC PERIOD EQUAL TO THE TIME TO COUNT A PREDETERMINED NUMBER OF SAID REGULARLY-SPACED PULSES, SELECTING MEANS DERIVING SINGLE PULSES SELECTIVELY FROM EITHER SAID FIRST SET OF PULSES OR THE SECOND SET OF PULSES OCCURRING THEREBETWEEN, A MIXER CONNECTED TO SAID SIGNAL GENERATING MEANS AND OPERATIVE TO COMBINE SAID SINGLE PULSES FROM SAID SECOND SET DERIVED IN SAID SELECTING MEANS TO MERGE WITH SAID COMMAND PULSES WITH THE REGULARLYSPACED PULSES TO ADD A PULSE BETWEEN TWO OF THE REGULARLY SPACED PULSES WHEREBY THE OUTPUT OF THE COUNTER IS ADVANCED BY THE DURATION OF ONE COIUNT, SAID MIXER ALSO HAVING MEANS OPERABLE FROM SAID SELECTING MEANS TO SUBTRACT ONE OF THE PULSES FROM SAID REGULARLY SPACED PULSES RESPONSIVE TO THE SINGLE PULSE DERIVED FROM THE FIRST SET OF PULSES WHEREBY THE OUTPUT OF THE COUNTER IS DELAYED BY THE DURATION OF ONE COUNT, DETECTOR MEANS FOR SENSING ERRORS IN THE POSITION OF SAID MOVABLE LOAD, MEANS OPERABLE SYNCHRONOUSLY FROM SAID PULSE GENERATING MEANS DERIVING IN SAID DETECTOR MEANS A POSITION SIGNAL, MEANS RESPONSIVE TO SAID POSITION SIGNAL FOR DERIVING A CONTROL SIGNAL FROM SAID COUNTER OUTPUT, AND A DRIVING MOTOR CONNECTED TO RECEIVE THE CONTROL SIGNAL AND CONTROL THE MOVEMENT OF SAID LOAD IN ACCORDANCE WITH SAID CONTROL SIGNAL.