Title :
Amorphous wire MI micro magnetic sensor for gradient field detection
Author :
Bushida, K. ; Mohri, K. ; Kanno, T. ; Katoh, D. ; Kobayashi, Akihiro
Author_Institution :
Dept. of Electr. Eng., Nagoya Univ., Japan
fDate :
9/1/1996 12:00:00 AM
Abstract :
A sensitive and quick response micro magnetic sensor for detection of a very localized field (gradient field) cancelling background disturbance field is presented using a high frequency (20~40 MHz) multivibrator having a pair of amorphous wire MI heads each of 1~3 mm in length. The resolution of field detection is 10-6 Oe for an ac field and the cut-off frequency is about 200 kHz. Stable detection of the surface field of a densely magnetized ring magnet with 19 mm diameter and 2000 poles (30 μm in pole interval) for a high resolution rotary encoder was carried out with a sinusoidal waveform
Keywords :
amorphous magnetic materials; magnetic field measurement; magnetic sensors; magnetoresistive devices; multivibrators; 1 to 3 mm; 19 mm; 20 to 40 MHz; 200 kHz; ac field; amorphous wire MI micromagnetic sensor; background disturbance field cancellation; cut-off frequency; densely magnetized ring magnet; field detection resolution; gradient field detection; high frequency multivibrator; high resolution rotary encoder; magnetoimpedance element; sinusoidal waveform; surface field detection; Amorphous materials; Circuits; Frequency; Impedance; Magnetic heads; Magnetic sensors; Modular construction; Permeability; Voltage; Wire;
Journal_Title :
Magnetics, IEEE Transactions on
