Design of a Novel Magnetic Field Generator Applied in Dynamic Characteristics Measurement of Magneto-dependent Sensors

The dynamic characteristics of magneto-dependent sensors are utilized in many fields. However, test equipment which can make an accurate evaluation of dynamic characteristics of magneto-dependent sensors is still limited by the difficulty of generating weak pulsed magnetic fields with narrow widths. In this paper, the operation of a novel pulsed magnetic field generator is presented at first. The core principle is to utilize a pressurized gas source to drive a permanent magnet past a static magnet at high speed. Thus, a weak pulsed magnetic field can be obtained with the pulse width determined by the speed of moving magnet. After that, the structural design of the magnetic field generator is demonstrated, with a simulation analysis of the magnetic field characteristics carried out simultaneously. Lastly, lab tests of the equipment are presented to verify the feasibility of the design. The results show that the novel magnetic field generator can obtain a weak pulsed magnetic field with a milliseconds pulse width. The generated magnetic field can be determined accurately through measuring the displacement of the moving magnet as well as the time it takes through the device. Thus the proposed equipment can provide a standard dynamic magnetic field for the study of dynamic characteristics of magneto-dependent sensors.