Capacitive pickup device for pulsating high voltage measurements

Claim 1

A capacitive pickup device for deriving a measurable voltage which is a linear function of the magnitude of pulsating high voltage in an insulated conductor, comprising: a pair of electrically conducting generally semicylindrical plate members connected together electrically to form a first plate element of a capacitor; means mounting said plate members for relative movement so they selectively may open for receiving an insulated conductor without requiring conductor disconnection and close to form substantially a cylinder closely encircling the conductor, the conductor forming a second plate element of the capacitor and the insulation thereon forming the dielectric between the two plate elements; a pair of electrically insulating members having concave faces respectively secured to the convex faces of said plate members and extending beyond the ends of said plate members; a pair of electrically conducting generally semicylindrical plates respectively secured to the concave faces of said insulating members in spaced relation with said plate members, said plates centrally relieved to accommodate said plate members and adapted to be connected to ground, said plates functioning to minimize the fringing effects of extraneous electric fields on the voltage appearing on said plate members; and voltage limiting output means electrically connected between said plate members and said plates to provide high voltage protection to the user and associated apparatus and to form an output circuit for connection to apparatus for indicating in linear manner the magnitude of the high voltage in the conductor.