US 4,727,316 A · Transformer current sensor for superconducting magnetic coils

Abstract

A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.

Claims9

Dependent claims

a transformer current sensor for detecting resistance voltage losses in a superconducting coil comprising:

cylindrical primary terms arranged in series with said superconducting coil to carry a primary current;
and
cylindrical secondary terms including an active winding and a dummy winding, said active winding and said dummy winding being coaxial, of substantially the same construction and arranged to mutually negate voltages induced by any commonly experienced magnetic field, said active winding but not said dummy winding being fixedly arranged coaxially within and substantially longitudinally coextensive with said primary turns, and said dummy winding being longitudinally separated form said active winding sufficient distance that said dummy winding is not influenced by magnetic fields generated by said primary current passing through said primary turns.

Dependencies are inferred from the claim text.

Transformer current sensor for superconducting magnetic coils

Life of this patent

Transformer current sensor for superconducting magnetic coils

Life of this patent

Abstract

Claims9