1993 Volume 113 Issue 3 Pages 387-393
Direct linear motion drive can be obtained by the use of linear pulse motor (LPM), Miniaturized LPMs have been applied to 3.5" floppy disk drive (FDD) units. It is necessary to control through feedback of position informations for higher performance. However, to miniaturize the units, sensorless detection of position of LPM is required.
In this paper, we dicussed a detection method using exciting winding of permanent magnet type LPM, and dealt with the followings.
(1) An equation of equivalent inductance contributing to flux by permanent magnet was led from magnetic equivalent circuit on permanent magnet type LPM. As a result, the relation between the inductances for each flux by permanent magnet and those by exciting winding was clarified.
(2) We showed the principle of position detection using LPM' s exciting winding as detection device, and showed the equivalent inductance can be detected from exciting voltage and current of LPM' s exciting winding.
(3) A good experimental result was obtaind through the application of the position detection method discussed in this paper to miniature LPM for 3.5" FDD.