Nondestructive toroidal memory core

By metal-cladding and drawing of semihard and soft magnetic materials, a simple toroidal core which has a nondestructive memory function was developed. The nondestructive property arises from the shift of the minor loop in the composite magnetic characteristic. The shift occurs either in the first and the third quadrants, or in the second and the fourth quadrants. This toroidal core utilizes the second type of shift, which is due to the exchange force between the two magnetic materials. The information is stored by means of the remanent state of the semi-hard magnetic material, and is read out through magnetization reversal of the soft magnetic material.