Field distribution of plated wire memory elements and its effect on memory characteristics

An approximate method is presented for the solution of magnetic field distribution in plated wires. By treating only the essential parameters of the distribution and ignoring its fine details, a simple and general solution is obtained, portraying the relation between the distribution shape, the geometry of the drive lines, and the magnetic characteristics of the wire. The results indicate the existence of a characteristic length λ over which the applied field tends to be averaged and which represents the lowest practical limit of bit size. Several examples, involving adjacent bit interaction, drive current requirement, sense signal amplitude, and tolerance analysis, demonstrate the efficiency and flexibility of the described method as a practical tool for the magnetic design of plated wire memories.