Displacement control system

Claim 1

A ELECTRONIC CONTROL SYSTEM FOR POSITIONING A MOVABLE MEMBER, SAID SYSTEM COMPRISING TRANSDUCER MEANS FOR PRODUCING A SIGNAL REPRESENTATIVE OF THE ACTUAL POSITION OF THE MOVBALE MEMBER, AN ACTUATING DEVICE FOR DISPLACING SAID MOVABLE MEMBER, SEQUENTIAL COUNTING MEANS, MEMORY MEANS STORING AT LEAST ONE ANALOGUE ELECTRONIC ENDLESS GRADUATION OF SIGNALS CORRESPONDING TO A SUCCESSION OF POSITIONS OF THE MOVABLE MEMBER, A READER FOR DELIVERING PULSE TRAINS REPRESENTING REPETITIVE READINGS OF THE SIGNALS OF SAID GRADUATION, A COUNTER RECEIVING SAID PULSE TRAINS, SAID COUNTER HAVING A NUMBER OF OUTPUTS CORRESPONDING TO THE NUMBER OF DIVISIONS OF THE SAID GRADUATION AND THUS TO THE NUMBER OF PULSES CONTAINED IN EACH PULSE TRAIN, SAID COUNTER DELIVERING ON EACH OUTPUT PULSES CORRESPONDING TO THE ORDER NUMBER OF THE SAID OUTPUT; SELECTOR MEANS FOR DELIVERING A SIGNAL FROM AT LEAST ONE OF THE SAID OUTPUTS OF SAID COUNTER, AND COMPARATOR MEANS FOR COMPARING THE SIGNALS DELIVERED BY THE TRANSDUCER MEANS AND THE SIGNALS DELIVERED FROM A SELECTED OUTPUT OF THE COUNTER, SAID COMPARATOR YIELDING AN ERROR SIGNAL, AND MEANS CONNECTING SAID COMPARATOR TO SAID ACTUATING DEVICE WHEREBY SAID ERROR SIGNAL CONTROLS SAID ACTUATING DEVICE AND IN TURN MOVEMENT OF SAID MEMBER.