BEMF crossing detection in PWM mode operation for sensorless motor control application
US5789895A · kind A · utility
29Cited by
14References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 12, 1996 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Dec 12, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/182
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and a circuit for detecting zero crossing points for a brushless, sensorless, three-phase DC motor operated in a PWM mode. The circuit senses a BEMF signal in a floating coil and generates a first signal when the BEMF signal is separated from the center tap voltage by a selected offset voltage amount. The circuit overrides the PWM mode and drives a high side driving transistor to a conducting state until the zero crossing point is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.