Direct current brushless motor and driving method therefor
US5814957A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 13, 1997 |
| Grant date | Sep 29, 1998 |
| Priority date | — |
| Expiry date | Feb 13, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/21
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A direct current brushless motor has a control unit (8) for controlling a commutation of current flowing in a stator winding (3), a duty ratio of an applied voltage to the stator winding (3), and a carrier period for the duty ratio. The control unit (8) switches over between a first operating mode at a starting operation and a second operating mode at an ordinary operation in accordance with at least one of a rotational speed of the rotor (2) and time length from starting of the first starting mode. The control means (8) adjust the carrier period so that a first setting value to be adjusted in the first operating mode is larger than a second setting value to be adjusted in the second operating mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.