Stepper motor with vernier control mode
US5208523A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 10, 1992 |
| Grant date | May 4, 1993 |
| Priority date | — |
| Expiry date | Mar 10, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/584
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A stepper motor in a magnetic tape cartridge head positioning system applies vernier control to achieve a final target after a preliminary target has been achieved by stepping. The vernier control is provided by a closed loop servo system in which current is applied to stator coils selected so that the target is at a torque maximum rather than at a torque null. Current proportional to a servo error signal is applied to selected stator coils so that the torque is sufficiently linearly related to position to permit classical linear servo analysis for the design of a stable, non-oscillating system. An example of stator coil selection for advancing and retarding a permanent magnet stepper motor operated in eight half steps is provided below in Table 1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.