Brushless generating system regulator which shunts excitation current from the fieldwinding

Claim 1

IN A REGULATED ELECTRIC GENERATING SYSTEM HAVING A GENERATOR WHOSE ALTERNATING OUTPUT POWER VARIES WITH THE ELECTRICAL EXCITATION DELIVERED TO A GENERATOR EXCITER, THE COMBINATION OF (A) SENSING MEANS FOR COUPLING WITH THE GENERATOR OUTPUT POWER TO PRODUCE A SENSED VOLTAGE PROPORTIONAL TO ONE PARAMETER OF THE ELECTRIC POWER OUTPUT FROM SAID GENERATOR, SAID SENSING MEANS COMPRISING (1) A WINDING LINKING THE GENERATOR OUTPUT POWER, AND (2) A SERIES RESISTOR-CAPACITOR CIRCUIT IN PARALLEL WITH SAID WINDING, (A) THE IMPEDANCE OF THE COMBINATION OF SAID WINDING AND SAID RESISTOR-CAPACITOR CIRCUIT BEING SUBSTANTIALLY UNIFORM OVER THE FREQUENCY RANGE OF THE ALTERNATING GENERATOR OUTPUT VOLTAGE (I) WHEREBY SAID SENSED VOLTAGE IS SUBSTANTIALLY INDEPENDENT OF THE FREQUENCY OF THE GENERATOR OUTPUT VOLTAGE (B) REFERENCE MEANS HAVING AN IMPEDENCE CHARACTERISTIC THAT HAS A NONLINEARITY AT A THRESHOLD VOLTAGE, (C) ELECTRONIC MEANS FOR APPLYING A CONTROLLED IMPEDANCE IN PARALLEL WITH THE EXCITATION DELIVERED TO THE EXCITER, (1) SAID ELECTRONIC MEANS BEING CONNECTED WITH SAID SENSING MEANS AND SAID REFERENCE MEANS TO RECEIVE A REGULATING SIGNAL PROPORTIONAL TO THE DIFFERENCE BETWEEN SAID SENSED VOLTAGE AND SAID THRESHOLD VOLTAGE, (2) TO CONTROL SAID IMPEDANCE IN RESPONSE TO SAID REGULATING SIGNAL TO REGULATE THE OUTPUT POWER FROM THE GENERATOR.