Magnetic Field Simulation in Embedded System with Magneto-Resistive Sensor

摘要

Anisotropic magnetoresistive (AMR) sensors are widely used in different applications [1,2] for detection of the Earth or other objects magnetic field weak changes. AMR sensor can be used to measure DC and AC current by sensing the field near the conductor in a contactless way [3] or vehicle predictive crash detection [4]. These sensors are very sensitive to temperature changes [5] and parasitic magnetic fields. This raises the natural question - what influence makes components of embedded system to AMR sensor? All components of the system that can be magnetized or produces magnetic field has influence on sensor. That could be controller, inductors of DC/DC converter, LED drivers (Fig. 1), data buss, power wires and etc. Even though most of the modern controllers and AMR sensors require little current, but network of 100 units may consume 3 to 10 A. Magnetic field sensor attached to active network (RS485 buss) was chosen for modeling. Sensors are connected to a single power supply wire (in series).