Potential device with input reactance adjustment

Claim 1

In combination with a high voltage capacitive voltage divider having high voltage terminals adapted for connection to a source of alternating current voltage of the order of 500 to 1,500 kilovolts in magnitude, said voltage divider including a pair of low voltage tap terminals and having a predetermined low capacitive reactance therebetween, a potential device adapted for connection between said low voltage tap terminals and an electrical load comprising, a high reactance transformer having a primary input winding for connection across said tap terminals, a tertiary winding closely coupled to said primary winding and a secondary winding loosely coupled to said primary winding, a variable capacitive impedance connected between one end of said tertiary winding and a point on said secondary winding to operate in shunt circuit relation with at least a portion of said secondary winding, said variable capacitive impedance being tunable toward resonance with respect to the equivalent inductive reactance of said transformer thereby to increase the equivalent inductive reactance of said potential device from a minimum value toward a maximum resonant value, an adjustable capacitive impedance connected across at least a portion of said tertiary winding, and means for selectably varying the magnitude of said adjustable capacitive impedance thereby to control the equivalent input capacitance between the tap terminals of said voltage divider, whereby the magnitude of said equivalent input capacitance may be set at a value greater than the minimum equivalent inductive reactance of said potential device and reactance matching is accomplished by increasing the equivalent inductive reactance of said potential device to a magnitude equal to the preset value of said equivalent input capacitance.