This document introduces the KMY 20 M magnetic field sensor and its application in thin film technology. The sensor is made of magnetoresistive material Permalloy, which has high sensitivity and small size. The special feature of this sensor is the integration of a permanent magnet, eliminating the need for external auxiliary fields.
The KMY 20M sensor uses a magnetoresistive permalloy element arranged in a Wheatstone bridge. Its output voltage is proportional to the magnetic field component Hy, and a permanent auxiliary field of 3 kA/m stabilises operation without external magnets.
The sensor integrates a permanent magnet, allowing safe operation in disturbing fields up to 30 kA/m. Technical data include a 12 V supply, 120 mW power dissipation, wide temperature ranges, and bridge resistance of 1.4‑2.2 kΩ. Applications cover weak‑field detection, contact‑less switches, displacement and speed measurement, angle sensing and galvanically isolated current measurement.