Title :
A magnetic bubble device for revolution counters
Author :
Iino, Toshio ; Tsukasa, T. ; Fujino, Kenji
Author_Institution :
Yokogawa Electr. Corp., Tokyo, Japan
fDate :
9/1/1999 12:00:00 AM
Abstract :
A magnetic bubble device (MBD) for revolution counters used for servomotors has been developed. This sensor was designed to count 32487 revolutions with only a 152 bit memory. A magnetic garnet film was chosen so that a wide propagation margin was achieved. The thickness of the film was also optimized so that the bubbles were stretched at a high bias field. The thickness of SiO2 was chosen to obtain a wide pulse width. The developed MBD achieved wide margins as follows: propagation margin and stretch margin were 25, 24 Oe respectively in the bias field direction, and pulse width margin was 5.6 μsec
Keywords :
angular measurement; magnetic bubble memories; magnetic sensors; magnetic thin film devices; servomotors; 152 bit; absolute encoder; high bias field; magnetic bubble device; magnetic bubble memory; magnetic garnet film; optimized film thickness; revolution counters; servomotors; shift register loops; stretch margin; wide propagation margin; Bidirectional control; Counting circuits; Frequency; Garnet films; Magnetic devices; Magnetic sensors; Propulsion; Servomotors; Shafts; Space vector pulse width modulation;
Journal_Title :
Magnetics, IEEE Transactions on
