Flux Gate Methodology
The IsoBlock I-FG-4C uses Flux-Gate methodology to measure the current flowing through the input conductor. This technique works by placing a toroid with a high number of turns (secondary) around the input current path (primary), while a close-loop circuitry controls the current through the secondary to null out the magnetic field inside the toroid. The input current is then obtained by multiplying the current from the control circuitry by the number of turns of the secondary. This is followed by an anti-aliasing filter and a conditioning stage to output a ±5V signal.