Method and apparatus for controlling a stepper motor
US4489259A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1982 |
| Grant date | Dec 18, 1984 |
| Priority date | — |
| Expiry date | Apr 29, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/41248
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for controlling a stepper motor and a disk drive is described for minimization of stepper motor oscillations for a single step, minimizing the time taken for the stepper motor to move between tracks for multi-track seeks, and reduction of angular hysteresis due to the mechanical and magnetic properties of the stepper motor construction. This control is achieved using a microprocessor-based circuit adapted to drive the stepper motor in accordance with predetermined programs. Oscillations of the stepper motor are damped by controlling, using one program, the current applied to the stepper motor during the last step of its motion by switching this current on and off within small predetermined time intervals. The time taken to move between tracks is controlled by another program in which the non-linear torque speed characteristics of a particular stepper motor are matched by a non-linear pulse rate which is determined by data held in the memory of the microprocessor circuit. This data can be modified to suit the requirements of the stepper motor and load. Another program controls minimization of hysteresis by ensuring that each track on the disk is approached fro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.