Generator-fed motor speed control with both reference and feedback damping

Claim 1

AN ERROR DETECTOR FOR A D-C MOTOR AND CONTROL SYSTEM WHEREIN A D-C MOTOR HAS AN ARMATURE ENERGIZED BY A VARIABLE D-C POWER SUPPLY THAT IS ADAPTED TO BE CONTROLLED BY AN ELECTRICAL ERROR SIGNAL TO VARY ITS OUTPUT TO SAID ARMATURE, IN COMBINATION THEREWITH, A FEEDBACK SIGNAL SOURCE CONNECTED TO SENSE THE VOLTAGE DROP ACROSS SAID ARMATURE AND TO EMIT A D-C FEEDBACK SIGNAL VOLTAGE OF MAGNITUDE PROPORTIONAL TO THE SPEED OF SAID D-C MOTOR; A REFERENCE SIGNAL SOURCE INCLUDING A VARIABLE D-C SOURCE ADJUSTABLE TO EMIT A D-C REFERENCE VOLTAGE AT ITS OUTPUT PROPORTIONAL TO A DESIRED SPEED FOR SAID D-C MOTOR; A DAMPING CIRCUIT INCLUDING A RESISTOR AND A CAPACITOR CONNECTED IN SERIES BETWEEN THE OUTPUT OF SAID FEEDBACK SIGNAL SOURCE AND THE OUTPUT OF SAID REFERENCE SIGNAL SOURCE; A FIRST COMPARISON CIRCUIT INCLUDING AN NPN TRANSISTOR WITH A BASE-EMITTER CIRCUIT CONNECTED AS SAID INPUT ACROSS SAID OUTPUT OF SAID REFERENCE SIGNAL SOURCE AND SAID OUTPUT OF SAID FEEDBACK SIGNAL SOURCE, AND AN EMITTER-COLLECTOR CIRCUIT CONNECTED IN SERIES WITH A D-C SOURCE FOR ERROR SIGNAL TO CONTROL THE FLOW OF SAID ERROR SIGNAL TO SAID VARIABLE D-C POWER SUPPLY;