Brushless DC motor
US5144209A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1991 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Jun 28, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2209/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A brushless DC motor which does not have a position sensor for detecting a rotational point of a rotor, instead of using a position sensor, detects the zero-crossing points of counter electromotive forces induced in the stator windings of the motor to obtain a pulse signal train. From the pulse signal train thus obtained and a slant waveform signal generated in response to the pulse signal train, a position signal with a trapezoidal waveform is formed. An electric current signal with a trapezoidal waveform is supplied to the stator windings of the motor in response to the position signal thus formed for effecting an electric current switching of the stator windings smoothly, resulting in realizing a motor drive which is less in vibration and noise even when rotating at a high speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.