DATA TABLET UTILIZING MATTEUCCI EFFECT OF AMORPHOUS MAGNETIC WIRE MATRIX

A new accurate and reliable data tablet or digitizer is constructed utilizing the Matteucci effect for amorphous magnetic wire matrix. Cold-drawn amorphous wires with 50-mu-m diameter having a composition of (Fe6 Co94)72.5Si12.5B15 were used in a tablet plane. An ac magnetic field of 140 kHz was perpendicularly applied to the amorphous wires to induce a double frequency Matteucci voltage between both ends of each amorphous wire. A small dc current of 2 - 5 mA was applied to the wire-axial direction for initial setting of its circular magnetization direction when the Matteucci voltage was detected. External disturbance fields did not influence on the Matteucci effect in the folded amorphous wires with a small dc current. Hand written characters were shown on a CRT display using the data tablet.