Detection of AC or DC in relatively compact device - stimulating high permeability core with HF current with magnetic field shifting hysteresis curve coercivity range

摘要

A.c. or d.c. is detected using a high permeability iron core (1a) with rectangular hysteresis curve and a stimulation coil (7) supplied (9) with HF current via a circuit connected to a detection resistance (8). The core is stimulated under identical conditions in the positive and negative regions and magnetised above the hysteresis curve coercitivity force range. - This range is displaced to change the stimulation current in reaction to applying a magnetic field. A resulting difference in the positive and negative voltages yields the measurement current value.