The effect of drive-wire position on square-loop ferrite toroidal core performance

Investigations of square-loop ferrite toroids have established that disturbed 1 and 0 signals, as well as delta noise, are a function of the location of the drive wire within the aperture of the core. Experimental results indicate that the disturbed 0 as well as the delta noise increases as the relative displacement of the drive wire from the center of the core is increased. The disturbed 1 decreases with increasing relative displacement. Data are presented that demonstrate the effect of relative displacement and remanent permeability on the disturbed O as a function of the disturb current. Results are also presented for the effect of displacement on delta noise and the disturbed 1. The data indicate that the amount of irreversible flux switched by the disturb pulses increases as the relative displacement of the drive wire from the center of the core increases. Interpretation of the data utilizes Hammond's solution for the fields in a cylinder of constant permeability driven by an off-center drive wire.