Control for electrical coupling apparatus

Claim 1

A CONTROL FOR ELECTRICAL APPARATUS HAVING A DRIVING MEMBER, A ROTATING DRIVEN MEMBER, AND ELECTRICAL COUPLING APPARATUS HAVING A FIELD COIL FOR CONTROLLING THE DEGREE OF COUPLING BETWEEN SAID DRIVING MEMBER AND SAID DRIVEN MEMBER THEREBY TO VARY THE ANGULAR VELOCITY OF THE DRIVEN MEMBER, SAID CONTROL COMPRISING: A GENERATOR DRIVEN BY SAID DRIVEN MEMBER FOR PRODUCING AN A.C. SIGNAL HAVING AN AMPLITUDE PROPORTIONAL TO THE ANGULAR VELOCITY OF SAID DRIVEN MEMBER; MEANS FOR RECTIFYING AND PARTIALLY FILTERING SAID A.C. SIGNAL ELECTRICALLY INTERCONNECTED WITH SAID GENERATOR TO SUPPLY A COMPOSITE ELECTRICAL SIGNAL HAVING AN A.C. COMPONENT AND A D.C. COMPONENT BEING PROPORTIONAL TO TUDE OF THE D.C. COMPONENT BEING PROPORTIONAL TO THE ANGUALR VELOCITY OF SAID DRIVEN MEMBER; A POWER SUPPLY HAVING FIRST AND SECOND OUTPUT TERMINALS; AN AMPLIFIER FOR ENERGIZING SAID FIELD COIL, SAID AMPLIFIER INCLUDING AN INPUT TRANSISTOR ANDA POWER TRANSISTOR, EACH OF SAID TRANSISTORS HAVE BASE, EMITTER, AND COLLECTER ELEMENTS, THE COLLECTOR OF SAID INPUT TRANSISTOR BEING CONNECTED TO SAID FIRST OUTPUT TERMINAL BY A COLLECTOR RESISTOR, SAID FIELD COIL BEING CONNECTED BETWEEN THE COLLECTOR OF SAID POWER TRANSISTOR AND SAID FIRST TERMINAL, THE EMITTERS OF SAID TRANSISTORS BEING CONNECTED TO SAID SECOND TERMINAL, THE BASE OF SAID POWER TRANSISTOR BEING COUPLED TO THE COLLECTOR OF SAID INPUT TRANSISTOR WHEREBY SAID POWER TRANSISTOR AMPLIFIES THE OUTPUT OF SAID INPUT TRANSISTOR; MEANS FOR APPLYING SAID COMPOSITE SIGNAL TO THE BASE OF SAID INPUT TRANSISTOR; AND MEANS FOR APPLYING TO THE BASE OF SAID INPUT TRANSISTOR A REFERENCE D.C. POTENTIAL THE MAGNITUDE OF WHICH IS PROPORTIONAL TO A PRESELECTED ANGULAR VELOCITY OF SAID DRIVEN MEMBER THEREBY TO CUT OFF SAID TRANSISTOR WHENEVER THE MAGNITUDE OF SAID COMPOSITE SIGNAL EXCEEDS SAID REFERENCE POTENTIAL BY A PRESELECTED AMOUNT, SAID MEANS FOR APPLYING A REFERENCE POTENTIAL INCLUDING A POTENTIOMETER HAVING A FIXED RESISTANCE CONNECTED BETWEEN SAID FIRST AND SECOND TERMINALS, A MOVABLE CONTACT ADAPTED TO BE POSITIONED IN ACCORDANCE WITH SAID PRESELECTED ANGULAR VELOCITY, AND A COUPLING RESISTOR CONNECTING SAID MOVABLE CONTACT TO THE BASE OF SAID INPUT TRANSISTOR WHEREBY SAID INPUT TRANSISTOR IS REPETITIVELY PULSED BETWEEN ITS CONDUCTING AND CUTOFF STATES AND THE RELATIVE RATIO BETWEEN ITS PERIODS OF CONDUCTION AND CUTOFF CONTROLS THE AVERAGE LEVEL OF THE ELECTRICAL POWER SUPPLIED TO SAID FIELD COIL BY SAID POWER TRANSISTOR THEREBY TO VARY THE DEGREE OF COUPLING BETWEEN THE DRIVING MEMBER AND THE DRIVEN MEMBER TO MAINTAIN THE ANGULAR VELOCITY OF SAID DRIVEN MEMBER SUBSTANTIALLY EQUAL TO SAID PRESELECTED ANGULAR VELOCITY.