An improved ac/dc current comparator

A novel design of the magnetic cores, windings and means of the excitation and detection for an improved ac/dc current comparator is disclosed. The system enables accurate measurements of ac current only or dc current only, or both simultaneous ac and dc current with a pair of detection cores and windings only. For the same order sensitivity of ac/dc current detection, the cost and weight of the improved ac/dc current comparator decrease by 30-percent, while the magnetic shielding effectiveness increases by 10-percent compared with the normal ac/dc current comparator for the 5000-A prototype