Sensorless brushless motor
US5182499A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1991 |
| Grant date | Jan 26, 1993 |
| Priority date | — |
| Expiry date | Oct 22, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2209/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a sensorless brushless motor which does not have a position sensor for detecting a rotational position of a rotor, the rotational position thereof is detected by detecting the zero-crossing points of the counter electromotive forces induced in the stator windings of the rotor. A shaping signal obtained by detecting the zero-crossing point of each of the counter electromotive forces and a slant waveform signal generated in response to the shaping signal thus obtained are combined to form a trapezoidal waveform position signal, and an electric current of a trapezoidal waveform is supplied in response to the position signal thus obtained to the corresponding one of the stator windings, so that the electric current commutation of the stator windings can be performed smoothly. As a result, the motor can be practically driven with reduced vibration and noise generation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.