Nondestructive readout by reversible flux changes

A study has been made of nondestructive readout of multipath memory cores which depend for their operation on the difference between the remanent and demagnetized permeabilities. The output flux change of an experimental core was measured as a function of the flux change in the interrogate branch during interrogation. It was found that the output flux change is a nonlinear function of the flux change in the interrogate branch. To explain these results it was necessary to assume that the reversible permeability is not a constant but depends linearly on the applied field. Using this assumption, a theory was developed which could be fit to the experimental data with a high degree of precision. The results of the analysis are applicable to the development of non-destructive readout (NDRO) memory devices which utilize the permeability difference effect.